Receiving a Power Headroom Value of a Reference Subframe During an Uplink Subframe

ABSTRACT

A base station transmits, during a first subframe, an uplink grant triggered in response to transmitting a trigger during a validation duration. The uplink grant indicates resource blocks. During the validation duration, the trigger indicating an uplink subframe for reception is transmitted via the resource blocks. A power headroom value determined for a reference subframe is received during the uplink subframe and via the resource blocks. The reference subframe: is after the first subframe; and is before the uplink subframe.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.16/215,346, filed Dec. 10, 2018, which is a continuation of U.S. Pat.No. 10,154,466 issued Dec. 11, 2018, which claims the benefit of U.S.Provisional Application No. 62/399,379, filed Sep. 24, 2016, all ofwhich are hereby incorporated by reference in their entireties.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

Examples of several of the various embodiments of the present disclosureare described herein with reference to the drawings.

FIG. 1 is a diagram depicting example sets of OFDM subcarriers as per anaspect of an embodiment of the present disclosure.

FIG. 2 is a diagram depicting an example transmission time and receptiontime for two carriers in a carrier group as per an aspect of anembodiment of the present disclosure.

FIG. 3 is an example diagram depicting OFDM radio resources as per anaspect of an embodiment of the present disclosure.

FIG. 4 is an example block diagram of a base station and a wirelessdevice as per an aspect of an embodiment of the present disclosure.

FIG. 5A, FIG. 5B, FIG. 5C and FIG. 5D are example diagrams for uplinkand downlink signal transmission as per an aspect of an embodiment ofthe present disclosure.

FIG. 6 is an example diagram for a protocol structure with CA and DC asper an aspect of an embodiment of the present disclosure.

FIG. 7 is an example diagram for a protocol structure with CA and DC asper an aspect of an embodiment of the present disclosure.

FIG. 8 shows example TAG configurations as per an aspect of anembodiment of the present disclosure.

FIG. 9 is an example message flow in a random access process in asecondary TAG as per an aspect of an embodiment of the presentdisclosure.

FIG. 10 is an example diagram depicting a downlink burst as per anaspect of an embodiment of the present disclosure.

FIG. 11 depicts examples of activation/deactivation MAC control elementas per an aspect of an embodiment of the present disclosure.

FIG. 12 is an example diagram depicting trigger A and trigger B in a2-stage triggered grant as per an aspect of an embodiment of the presentdisclosure.

FIG. 13 is an example diagram depicting a PHR process for a two-stagegrant as per an aspect of an embodiment of the present disclosure.

FIG. 14 is an example diagram depicting a BSR process for a two-stagegrant as per an aspect of an embodiment of the present disclosure.

FIG. 15 is an example diagram depicting a PHR/BSR process when atwo-stage grant is invalidated as per an aspect of an embodiment of thepresent disclosure.

FIG. 16 is an example diagram depicting a MAC/PHY TB process for one ormore two-stage grants as per an aspect of an embodiment of the presentdisclosure.

FIG. 17 is an example flow diagram as per an aspect of an embodiment ofthe present disclosure.

FIG. 18 is an example flow diagram as per an aspect of an embodiment ofthe present disclosure.

DETAILED DESCRIPTION OF EMBODIMENTS

Example embodiments of the present disclosure enable operation ofcarrier aggregation. Embodiments of the technology disclosed herein maybe employed in the technical field of multicarrier communicationsystems.

The following Acronyms are used throughout the present disclosure:

-   -   ASIC application-specific integrated circuit    -   BPSK binary phase shift keying    -   CA carrier aggregation    -   CSI channel state information    -   CDMA code division multiple access    -   CSS common search space    -   CPLD complex programmable logic devices    -   CC component carrier    -   DL downlink    -   DCI downlink control information    -   DC dual connectivity    -   EPC evolved packet core    -   E-UTRAN evolved-universal terrestrial radio access network    -   FPGA field programmable gate arrays    -   FDD frequency division multiplexing    -   HDL hardware description languages    -   HARQ hybrid automatic repeat request    -   IE information element    -   LAA licensed assisted access    -   LTE long term evolution    -   MCG master cell group    -   MeNB master evolved node B    -   MIB master information block    -   MAC media access control    -   MAC media access control    -   MME mobility management entity    -   NAS non-access stratum    -   OFDM orthogonal frequency division multiplexing    -   PDCP packet data convergence protocol    -   PDU packet data unit    -   PHY physical    -   PDCCH physical downlink control channel    -   PHICH physical HARQ indicator channel    -   PUCCH physical uplink control channel    -   PUSCH physical uplink shared channel    -   PCell primary cell    -   PCell primary cell    -   PCC primary component carrier    -   PSCell primary secondary cell    -   pTAG primary timing advance group    -   QAM quadrature amplitude modulation    -   QPSK quadrature phase shift keying    -   RBG Resource Block Groups    -   RLC radio link control    -   RRC radio resource control    -   RA random access    -   RB resource blocks    -   SCC secondary component carrier    -   SCell secondary cell    -   Scell secondary cells    -   SCG secondary cell group    -   SeNB secondary evolved node B    -   sTAGs secondary timing advance group    -   SDU service data unit    -   S-GW serving gateway    -   SRB signaling radio bearer    -   SC-OFDM single carrier-OFDM    -   SFN system frame number    -   SIB system information block    -   TAI tracking area identifier    -   TAT time alignment timer    -   TDD time division duplexing    -   TDMA time division multiple access    -   TA timing advance    -   TAG timing advance group    -   TB transport block    -   UL uplink    -   UE user equipment    -   VHDL VHSIC hardware description language

Example embodiments of the disclosure may be implemented using variousphysical layer modulation and transmission mechanisms. Exampletransmission mechanisms may include, but are not limited to: CDMA, OFDM,TDMA, Wavelet technologies, and/or the like. Hybrid transmissionmechanisms such as TDMA/CDMA, and OFDM/CDMA may also be employed.Various modulation schemes may be applied for signal transmission in thephysical layer. Examples of modulation schemes include, but are notlimited to: phase, amplitude, code, a combination of these, and/or thelike. An example radio transmission method may implement QAM using BPSK,QPSK, 16-QAM, 64-QAM, 256-QAM, and/or the like. Physical radiotransmission may be enhanced by dynamically or semi-dynamically changingthe modulation and coding scheme depending on transmission requirementsand radio conditions.

FIG. 1 is a diagram depicting example sets of OFDM subcarriers as per anaspect of an embodiment of the present disclosure. As illustrated inthis example, arrow(s) in the diagram may depict a subcarrier in amulticarrier OFDM system. The OFDM system may use technology such asOFDM technology, DFTS-OFDM, SC-OFDM technology, or the like. Forexample, arrow 101 shows a subcarrier transmitting information symbols.FIG. 1 is for illustration purposes, and a typical multicarrier OFDMsystem may include more subcarriers in a carrier. For example, thenumber of subcarriers in a carrier may be in the range of 10 to 10,000subcarriers. FIG. 1 shows two guard bands 106 and 107 in a transmissionband. As illustrated in FIG. 1, guard band 106 is between subcarriers103 and subcarriers 104. The example set of subcarriers A 102 includessubcarriers 103 and subcarriers 104. FIG. 1 also illustrates an exampleset of subcarriers B 105. As illustrated, there is no guard band betweenany two subcarriers in the example set of subcarriers B 105. Carriers ina multicarrier OFDM communication system may be contiguous carriers,non-contiguous carriers, or a combination of both contiguous andnon-contiguous carriers.

FIG. 2 is a diagram depicting an example transmission time and receptiontime for two carriers as per an aspect of an embodiment of the presentdisclosure. A multicarrier OFDM communication system may include one ormore carriers, for example, ranging from 1 to 10 carriers. Carrier A 204and carrier B 205 may have the same or different timing structures.Although FIG. 2 shows two synchronized carriers, carrier A 204 andcarrier B 205 may or may not be synchronized with each other. Differentradio frame structures may be supported for FDD and TDD duplexmechanisms. FIG. 2 shows an example FDD frame timing. Downlink anduplink transmissions may be organized into radio frames 201. In thisexample, the radio frame duration is 10 msec. Other frame durations, forexample, in the range of 1 to 100 msec may also be supported. In thisexample, each 10 ms radio frame 201 may be divided into ten equallysized subframes 202. Other subframe durations such as 0.5 msec, 1 msec,2 msec, and 5 msec may also be supported. Subframe(s) may consist of twoor more slots (for example, slots 206 and 207). For the example of FDD,10 subframes may be available for downlink transmission and 10 subframesmay be available for uplink transmissions in each 10 ms interval. Uplinkand downlink transmissions may be separated in the frequency domain.Slot(s) may include a plurality of OFDM symbols 203. The number of OFDMsymbols 203 in a slot 206 may depend on the cyclic prefix length andsubcarrier spacing.

FIG. 3 is a diagram depicting OFDM radio resources as per an aspect ofan embodiment of the present disclosure. The resource grid structure intime 304 and frequency 305 is illustrated in FIG. 3. The quantity ofdownlink subcarriers or RBs (in this example 6 to 100 RBs) may depend,at least in part, on the downlink transmission bandwidth 306 configuredin the cell. The smallest radio resource unit may be called a resourceelement (e.g. 301). Resource elements may be grouped into resourceblocks (e.g. 302). Resource blocks may be grouped into larger radioresources called Resource Block Groups (RBG) (e.g. 303). The transmittedsignal in slot 206 may be described by one or several resource grids ofa plurality of subcarriers and a plurality of OFDM symbols. Resourceblocks may be used to describe the mapping of certain physical channelsto resource elements. Other pre-defined groupings of physical resourceelements may be implemented in the system depending on the radiotechnology. For example, 24 subcarriers may be grouped as a radio blockfor a duration of 5 msec. In an illustrative example, a resource blockmay correspond to one slot in the time domain and 180 kHz in thefrequency domain (for 15 KHz subcarrier bandwidth and 12 subcarriers).

FIG. 5A, FIG. 5B, FIG. 5C and FIG. 5D are example diagrams for uplinkand downlink signal transmission as per an aspect of an embodiment ofthe present disclosure. FIG. 5A shows an example uplink physicalchannel. The baseband signal representing the physical uplink sharedchannel may perform the following processes. These functions areillustrated as examples and it is anticipated that other mechanisms maybe implemented in various embodiments. The functions may comprisescrambling, modulation of scrambled bits to generate complex-valuedsymbols, mapping of the complex-valued modulation symbols onto one orseveral transmission layers, transform precoding to generatecomplex-valued symbols, precoding of the complex-valued symbols, mappingof precoded complex-valued symbols to resource elements, generation ofcomplex-valued time-domain DFTS-OFDM/SC-FDMA signal for each antennaport, and/or the like.

Example modulation and up-conversion to the carrier frequency of thecomplex-valued DFTS-OFDM/SC-FDMA baseband signal for each antenna portand/or the complex-valued PRACH baseband signal is shown in FIG. 5B.Filtering may be employed prior to transmission.

An example structure for Downlink Transmissions is shown in FIG. 5C. Thebaseband signal representing a downlink physical channel may perform thefollowing processes. These functions are illustrated as examples and itis anticipated that other mechanisms may be implemented in variousembodiments. The functions include scrambling of coded bits in each ofthe codewords to be transmitted on a physical channel; modulation ofscrambled bits to generate complex-valued modulation symbols; mapping ofthe complex-valued modulation symbols onto one or several transmissionlayers; precoding of the complex-valued modulation symbols on each layerfor transmission on the antenna ports; mapping of complex-valuedmodulation symbols for each antenna port to resource elements;generation of complex-valued time-domain OFDM signal for each antennaport, and/or the like.

Example modulation and up-conversion to the carrier frequency of thecomplex-valued OFDM baseband signal for each antenna port is shown inFIG. 5D. Filtering may be employed prior to transmission.

FIG. 4 is an example block diagram of a base station 401 and a wirelessdevice 406, as per an aspect of an embodiment of the present disclosure.A communication network 400 may include at least one base station 401and at least one wireless device 406. The base station 401 may includeat least one communication interface 402, at least one processor 403,and at least one set of program code instructions 405 stored innon-transitory memory 404 and executable by the at least one processor403. The wireless device 406 may include at least one communicationinterface 407, at least one processor 408, and at least one set ofprogram code instructions 410 stored in non-transitory memory 409 andexecutable by the at least one processor 408. Communication interface402 in base station 401 may be configured to engage in communicationwith communication interface 407 in wireless device 406 via acommunication path that includes at least one wireless link 411.Wireless link 411 may be a bi-directional link. Communication interface407 in wireless device 406 may also be configured to engage in acommunication with communication interface 402 in base station 401. Basestation 401 and wireless device 406 may be configured to send andreceive data over wireless link 411 using multiple frequency carriers.According to aspects of an embodiments, transceiver(s) may be employed.A transceiver is a device that includes both a transmitter and receiver.Transceivers may be employed in devices such as wireless devices, basestations, relay nodes, and/or the like. Example embodiments for radiotechnology implemented in communication interface 402, 407 and wirelesslink 411 are illustrated are FIG. 1, FIG. 2, FIG. 3, FIG. 5, andassociated text.

An interface may be a hardware interface, a firmware interface, asoftware interface, and/or a combination thereof. The hardware interfacemay include connectors, wires, electronic devices such as drivers,amplifiers, and/or the like. A software interface may include codestored in a memory device to implement protocol(s), protocol layers,communication drivers, device drivers, combinations thereof, and/or thelike. A firmware interface may include a combination of embeddedhardware and code stored in and/or in communication with a memory deviceto implement connections, electronic device operations, protocol(s),protocol layers, communication drivers, device drivers, hardwareoperations, combinations thereof, and/or the like.

The term configured may relate to the capacity of a device whether thedevice is in an operational or non-operational state. Configured mayalso refer to specific settings in a device that effect the operationalcharacteristics of the device whether the device is in an operational ornon-operational state. In other words, the hardware, software, firmware,registers, memory values, and/or the like may be “configured” within adevice, whether the device is in an operational or nonoperational state,to provide the device with specific characteristics. Terms such as “acontrol message to cause in a device” may mean that a control messagehas parameters that may be used to configure specific characteristics inthe device, whether the device is in an operational or non-operationalstate.

According to various aspects of an embodiment, an LTE network mayinclude a multitude of base stations, providing a user planePDCP/RLC/MAC/PHY and control plane (RRC) protocol terminations towardsthe wireless device. The base station(s) may be interconnected withother base station(s) (for example, interconnected employing an X2interface). Base stations may also be connected employing, for example,an S1 interface to an EPC. For example, base stations may beinterconnected to the MME employing the S1-MME interface and to the S-G)employing the S1-U interface. The S1 interface may support amany-to-many relation between MMEs/Serving Gateways and base stations. Abase station may include many sectors for example: 1, 2, 3, 4, or 6sectors. A base station may include many cells, for example, rangingfrom 1 to 50 cells or more. A cell may be categorized, for example, as aprimary cell or secondary cell. At RRC connectionestablishment/re-establishment/handover, one serving cell may providethe NAS (non-access stratum) mobility information (e.g. TAI), and at RRCconnection re-establishment/handover, one serving cell may provide thesecurity input. This cell may be referred to as the Primary Cell(PCell). In the downlink, the carrier corresponding to the PCell may bethe Downlink Primary Component Carrier (DL PCC), while in the uplink,the carrier corresponding to the PCell may be the Uplink PrimaryComponent Carrier (UL PCC). Depending on wireless device capabilities,Secondary Cells (SCells) may be configured to form together with thePCell a set of serving cells. In the downlink, the carrier correspondingto an SCell may be a Downlink Secondary Component Carrier (DL SCC),while in the uplink, it may be an Uplink Secondary Component Carrier (ULSCC). An SCell may or may not have an uplink carrier.

A cell, comprising a downlink carrier and optionally an uplink carrier,may be assigned a physical cell ID and a cell index. A carrier (downlinkor uplink) may belong to only one cell. The cell ID or Cell index mayalso identify the downlink carrier or uplink carrier of the cell(depending on the context it is used). In the specification, cell ID maybe equally referred to a carrier ID, and cell index may be referred tocarrier index. In implementation, the physical cell ID or cell index maybe assigned to a cell. A cell ID may be determined using asynchronization signal transmitted on a downlink carrier. A cell indexmay be determined using RRC messages. For example, when thespecification refers to a first physical cell ID for a first downlinkcarrier, the specification may mean the first physical cell ID is for acell comprising the first downlink carrier. The same concept may apply,for example, to carrier activation. When the specification indicatesthat a first carrier is activated, the specification may also mean thatthe cell comprising the first carrier is activated.

Embodiments may be configured to operate as needed. The disclosedmechanism may be performed when certain criteria are met, for example,in a wireless device, a base station, a radio environment, a network, acombination of the above, and/or the like. Example criteria may bebased, at least in part, on for example, traffic load, initial systemset up, packet sizes, traffic characteristics, a combination of theabove, and/or the like. When the one or more criteria are met, variousexample embodiments may be applied. Therefore, it may be possible toimplement example embodiments that selectively implement disclosedprotocols.

A base station may communicate with a mix of wireless devices. Wirelessdevices may support multiple technologies, and/or multiple releases ofthe same technology. Wireless devices may have some specificcapability(ies) depending on its wireless device category and/orcapability(ies). A base station may comprise multiple sectors. When thisdisclosure refers to a base station communicating with a plurality ofwireless devices, this disclosure may refer to a subset of the totalwireless devices in a coverage area. This disclosure may refer to, forexample, a plurality of wireless devices of a given LTE release with agiven capability and in a given sector of the base station. Theplurality of wireless devices in this disclosure may refer to a selectedplurality of wireless devices, and/or a subset of total wireless devicesin a coverage area which perform according to disclosed methods, and/orthe like. There may be a plurality of wireless devices in a coveragearea that may not comply with the disclosed methods, for example,because those wireless devices perform based on older releases of LTEtechnology.

FIG. 6 and FIG. 7 are example diagrams for protocol structure with CAand DC as per an aspect of an embodiment of the present disclosure.E-UTRAN may support Dual Connectivity (DC) operation whereby a multipleRX/TX UE in RRC_CONNECTED may be configured to utilize radio resourcesprovided by two schedulers located in two eNBs connected via a non-idealbackhaul over the X2 interface. eNB s involved in DC for a certain UEmay assume two different roles: an eNB may either act as an MeNB or asan SeNB. In DC a UE may be connected to one MeNB and one SeNB.Mechanisms implemented in DC may be extended to cover more than twoeNBs. FIG. 7 illustrates one example structure for the UE side MACentities when a Master Cell Group (MCG) and a Secondary Cell Group (SCG)are configured, and it may not restrict implementation. Media BroadcastMulticast Service (MBMS) reception is not shown in this figure forsimplicity.

In DC, the radio protocol architecture that a particular bearer uses maydepend on how the bearer is setup. Three alternatives may exist, an MCGbearer, an SCG bearer and a split bearer as shown in FIG. 6. RRC may belocated in MeNB and SRBs may be configured as a MCG bearer type and mayuse the radio resources of the MeNB. DC may also be described as havingat least one bearer configured to use radio resources provided by theSeNB. DC may or may not be configured/implemented in example embodimentsof the disclosure.

In the case of DC, the UE may be configured with two MAC entities: oneMAC entity for MeNB, and one MAC entity for SeNB. In DC, the configuredset of serving cells for a UE may comprise two subsets: the Master CellGroup (MCG) containing the serving cells of the MeNB, and the SecondaryCell Group (SCG) containing the serving cells of the SeNB. For a SCG,one or more of the following may be applied. At least one cell in theSCG may have a configured UL CC and one of them, named PSCell (or PCellof SCG, or sometimes called PCell), may be configured with PUCCHresources. When the SCG is configured, there may be at least one SCGbearer or one Split bearer. Upon detection of a physical layer problemor a random access problem on a PSCell, or the maximum number of RLCretransmissions has been reached associated with the SCG, or upondetection of an access problem on a PSCell during a SCG addition or aSCG change: a RRC connection re-establishment procedure may not betriggered, UL transmissions towards cells of the SCG may be stopped, anda MeNB may be informed by the UE of a SCG failure type. For splitbearer, the DL data transfer over the MeNB may be maintained. The RLC AMbearer may be configured for the split bearer. Like a PCell, a PSCellmay not be de-activated. A PSCell may be changed with a SCG change (forexample, with a security key change and a RACH procedure), and/orneither a direct bearer type change between a Split bearer and a SCGbearer nor simultaneous configuration of a SCG and a Split bearer may besupported.

With respect to the interaction between a MeNB and a SeNB, one or moreof the following principles may be applied. The MeNB may maintain theRRM measurement configuration of the UE and may, (for example, based onreceived measurement reports or traffic conditions or bearer types),decide to ask a SeNB to provide additional resources (serving cells) fora UE. Upon receiving a request from the MeNB, a SeNB may create acontainer that may result in the configuration of additional servingcells for the UE (or decide that it has no resource available to do so).For UE capability coordination, the MeNB may provide (part of) the ASconfiguration and the UE capabilities to the SeNB. The MeNB and the SeNBmay exchange information about a UE configuration by employing RRCcontainers (inter-node messages) carried in X2 messages. The SeNB mayinitiate a reconfiguration of its existing serving cells (for example, aPUCCH towards the SeNB). The SeNB may decide which cell is the PSCellwithin the SCG. The MeNB may not change the content of the RRCconfiguration provided by the SeNB. In the case of a SCG addition and aSCG SCell addition, the MeNB may provide the latest measurement resultsfor the SCG cell(s). Both a MeNB and a SeNB may know the SFN andsubframe offset of each other by OAM, (for example, for the purpose ofDRX alignment and identification of a measurement gap). In an example,when adding a new SCG SCell, dedicated RRC signaling may be used forsending required system information of the cell as for CA, except forthe SFN acquired from a MIB of the PSCell of a SCG.

In an example, serving cells may be grouped in a TA group (TAG). Servingcells in one TAG may use the same timing reference. For a given TAG,user equipment (UE) may use at least one downlink carrier as a timingreference. For a given TAG, a UE may synchronize uplink subframe andframe transmission timing of uplink carriers belonging to the same TAG.In an example, serving cells having an uplink to which the same TAapplies may correspond to serving cells hosted by the same receiver. AUE supporting multiple TAs may support two or more TA groups. One TAgroup may contain the PCell and may be called a primary TAG (pTAG). In amultiple TAG configuration, at least one TA group may not contain thePCell and may be called a secondary TAG (sTAG). In an example, carrierswithin the same TA group may use the same TA value and/or the sametiming reference. When DC is configured, cells belonging to a cell group(MCG or SCG) may be grouped into multiple TAGs including a pTAG and oneor more sTAGs.

FIG. 8 shows example TAG configurations as per an aspect of anembodiment of the present disclosure. In Example 1, pTAG comprises aPCell, and an sTAG comprises SCell1. In Example 2, a pTAG comprises aPCell and SCell1, and an sTAG comprises SCell2 and SCell3. In Example 3,pTAG comprises PCell and SCell1, and an sTAG1 includes SCell2 andSCell3, and sTAG2 comprises SCell4. Up to four TAGs may be supported ina cell group (MCG or SCG) and other example TAG configurations may alsobe provided. In various examples in this disclosure, example mechanismsare described for a pTAG and an sTAG. Some of the example mechanisms maybe applied to configurations with multiple sTAGs.

In an example, an eNB may initiate an RA procedure via a PDCCH order foran activated SCell. This PDCCH order may be sent on a scheduling cell ofthis SCell. When cross carrier scheduling is configured for a cell, thescheduling cell may be different than the cell that is employed forpreamble transmission, and the PDCCH order may include an SCell index.At least a non-contention based RA procedure may be supported forSCell(s) assigned to sTAG(s).

FIG. 9 is an example message flow in a random access process in asecondary TAG as per an aspect of an embodiment of the presentdisclosure. An eNB transmits an activation command 600 to activate anSCell. A preamble 602 (Msg1) may be sent by a UE in response to a PDCCHorder 601 on an SCell belonging to an sTAG. In an example embodiment,preamble transmission for SCells may be controlled by the network usingPDCCH format 1A. Msg2 message 603 (RAR: random access response) inresponse to the preamble transmission on the SCell may be addressed toRA-RNTI in a PCell common search space (CSS). Uplink packets 604 may betransmitted on the SCell in which the preamble was transmitted.

According to an embodiment, initial timing alignment may be achievedthrough a random access procedure. This may involve a UE transmitting arandom access preamble and an eNB responding with an initial TA commandNTA (amount of timing advance) within a random access response window.The start of the random access preamble may be aligned with the start ofa corresponding uplink subframe at the UE assuming NTA=0. The eNB mayestimate the uplink timing from the random access preamble transmittedby the UE. The TA command may be derived by the eNB based on theestimation of the difference between the desired UL timing and theactual UL timing. The UE may determine the initial uplink transmissiontiming relative to the corresponding downlink of the sTAG on which thepreamble is transmitted.

The mapping of a serving cell to a TAG may be configured by a servingeNB with RRC signaling. The mechanism for TAG configuration andreconfiguration may be based on RRC signaling. According to variousaspects of an embodiment, when an eNB performs an SCell additionconfiguration, the related TAG configuration may be configured for theSCell. In an example embodiment, an eNB may modify the TAG configurationof an SCell by removing (releasing) the SCell and adding(configuring) anew SCell (with the same physical cell ID and frequency) with an updatedTAG ID. The new SCell with the updated TAG ID may initially be inactivesubsequent to being assigned the updated TAG ID. The eNB may activatethe updated new SCell and start scheduling packets on the activatedSCell. In an example implementation, it may not be possible to changethe TAG associated with an SCell, but rather, the SCell may need to beremoved and a new SCell may need to be added with another TAG. Forexample, if there is a need to move an SCell from an sTAG to a pTAG, atleast one RRC message, (for example, at least one RRC reconfigurationmessage), may be send to the UE to reconfigure TAG configurations byreleasing the SCell and then configuring the SCell as a part of thepTAG. When an SCell is added/configured without a TAG index, the SCellmay be explicitly assigned to the pTAG. The PCell may not change its TAgroup and may be a member of the pTAG.

The purpose of an RRC connection reconfiguration procedure may be tomodify an RRC connection, (for example, to establish, modify and/orrelease RBs, to perform handover, to setup, modify, and/or releasemeasurements, to add, modify, and/or release SCells). If the receivedRRC Connection Reconfiguration message includes the sCellToReleaseList,the UE may perform an SCell release. If the received RRC ConnectionReconfiguration message includes the sCellToAddModList, the UE mayperform SCell additions or modification.

In LTE Release-10 and Release-11 CA, a PUCCH may only be transmitted onthe PCell (PSCell) to an eNB. In LTE-Release 12 and earlier, a UE maytransmit PUCCH information on one cell (PCell or PSCell) to a given eNB.

As the number of CA capable UEs and also the number of aggregatedcarriers increase, the number of PUCCHs and also the PUCCH payload sizemay increase. Accommodating the PUCCH transmissions on the PCell maylead to a high PUCCH load on the PCell. A PUCCH on an SCell may beintroduced to offload the PUCCH resource from the PCell. More than onePUCCH may be configured for example, a PUCCH on a PCell and anotherPUCCH on an SCell. In the example embodiments, one, two or more cellsmay be configured with PUCCH resources for transmitting CSI/ACK/NACK toa base station. Cells may be grouped into multiple PUCCH groups, and oneor more cell within a group may be configured with a PUCCH. In anexample configuration, one SCell may belong to one PUCCH group. SCellswith a configured PUCCH transmitted to a base station may be called aPUCCH SCell, and a cell group with a common PUCCH resource transmittedto the same base station may be called a PUCCH group.

In an example embodiment, a MAC entity may have a configurable timertimeAlignmentTimer per TAG. The timeAlignmentTimer may be used tocontrol how long the MAC entity considers the Serving Cells belonging tothe associated TAG to be uplink time aligned. The MAC entity may, when aTiming Advance Command MAC control element is received, apply the TimingAdvance Command for the indicated TAG; start or restart thetimeAlignmentTimer associated with the indicated TAG. The MAC entitymay, when a Timing Advance Command is received in a Random AccessResponse message for a serving cell belonging to a TAG and/or if theRandom Access Preamble was not selected by the MAC entity, apply theTiming Advance Command for this TAG and start or restart thetimeAlignmentTimer associated with this TAG. Otherwise, if thetimeAlignmentTimer associated with this TAG is not running, the TimingAdvance Command for this TAG may be applied and the timeAlignmentTimerassociated with this TAG started. When the contention resolution isconsidered not successful, a timeAlignmentTimer associated with this TAGmay be stopped. Otherwise, the MAC entity may ignore the received TimingAdvance Command.

In example embodiments, a timer is running once it is started, until itis stopped or until it expires; otherwise it may not be running. A timercan be started if it is not running or restarted if it is running. Forexample, a timer may be started or restarted from its initial value.

Example embodiments of the disclosure may enable operation ofmulti-carrier communications. Other example embodiments may comprise anon-transitory tangible computer readable media comprising instructionsexecutable by one or more processors to cause operation of multi-carriercommunications. Yet other example embodiments may comprise an article ofmanufacture that comprises a non-transitory tangible computer readablemachine-accessible medium having instructions encoded thereon forenabling programmable hardware to cause a device (e.g. wirelesscommunicator, UE, base station, etc.) to enable operation ofmulti-carrier communications. The device may include processors, memory,interfaces, and/or the like. Other example embodiments may comprisecommunication networks comprising devices such as base stations,wireless devices (or user equipment: UE), servers, switches, antennas,and/or the like.

The amount of data traffic carried over cellular networks is expected toincrease for many years to come. The number of users/devices isincreasing and each user/device accesses an increasing number andvariety of services, e.g. video delivery, large files, images. This mayrequire not only high capacity in the network, but also provisioningvery high data rates to meet customers' expectations on interactivityand responsiveness. More spectrum may therefore needed for cellularoperators to meet the increasing demand. Considering user expectationsof high data rates along with seamless mobility, it may be beneficialthat more spectrum be made available for deploying macro cells as wellas small cells for cellular systems.

Striving to meet the market demands, there has been increasing interestfrom operators in deploying some complementary access utilizingunlicensed spectrum to meet the traffic growth. This is exemplified bythe large number of operator-deployed Wi-Fi networks and the 3GPPstandardization of LTE/WLAN interworking solutions. This interestindicates that unlicensed spectrum, when present, may be an effectivecomplement to licensed spectrum for cellular operators to helpaddressing the traffic explosion in some scenarios, such as hotspotareas. LAA may offer an alternative for operators to make use ofunlicensed spectrum while managing one radio network, thus offering newpossibilities for optimizing the network's efficiency.

In an example embodiment, Listen-before-talk (clear channel assessment)may be implemented for transmission in an LAA cell. In alisten-before-talk (LBT) procedure, equipment may apply a clear channelassessment (CCA) check before using the channel. For example, the CCAmay utilize at least energy detection to determine the presence orabsence of other signals on a channel in order to determine if a channelis occupied or clear, respectively. For example, European and Japaneseregulations mandate the usage of LBT in the unlicensed bands. Apart fromregulatory requirements, carrier sensing via LBT may be one way for fairsharing of the unlicensed spectrum.

In an example embodiment, discontinuous transmission on an unlicensedcarrier with limited maximum transmission duration may be enabled. Someof these functions may be supported by one or more signals to betransmitted from the beginning of a discontinuous LAA downlinktransmission. Channel reservation may be enabled by the transmission ofsignals, by an LAA node, after gaining channel access via a successfulLBT operation, so that other nodes that receive the transmitted signalwith energy above a certain threshold sense the channel to be occupied.Functions that may need to be supported by one or more signals for LAAoperation with discontinuous downlink transmission may include one ormore of the following: detection of the LAA downlink transmission(including cell identification) by UEs, time & frequency synchronizationof UEs, and/or the like.

In an example embodiment, a DL LAA design may employ subframe boundaryalignment according to LTE-A carrier aggregation timing relationshipsacross serving cells aggregated by CA. This may not imply that the eNBtransmissions can start only at the subframe boundary. LAA may supporttransmitting PDSCH when not all OFDM symbols are available fortransmission in a subframe according to LBT. Delivery of necessarycontrol information for the PDSCH may also be supported.

An LBT procedure may be employed for fair and friendly coexistence ofLAA with other operators and technologies operating in an unlicensedspectrum. LBT procedures on a node attempting to transmit on a carrierin an unlicensed spectrum may require the node to perform a clearchannel assessment to determine if the channel is free for use. An LBTprocedure may involve at least energy detection to determine if thechannel is being used. For example, regulatory requirements in someregions, for example, in Europe, may specify an energy detectionthreshold such that if a node receives energy greater than thisthreshold, the node assumes that the channel is not free. While nodesmay follow such regulatory requirements, a node may optionally use alower threshold for energy detection than that specified by regulatoryrequirements. In an example, LAA may employ a mechanism to adaptivelychange the energy detection threshold. For example, LAA may employ amechanism to adaptively lower the energy detection threshold from anupper bound. Adaptation mechanism(s) may not preclude static orsemi-static setting of the threshold. In an example a Category 4 LBTmechanism or other type of LBT mechanisms may be implemented.

Various example LBT mechanisms may be implemented. In an example, forsome signals, in some implementation scenarios, in some situations,and/or in some frequencies, no LBT procedure may performed by thetransmitting entity. In an example, Category 2 (for example, LBT withoutrandom back-off) may be implemented. The duration of time that thechannel is sensed to be idle before the transmitting entity transmitsmay be deterministic. In an example, Category 3 (for example, LBT withrandom back-off with a contention window of fixed size) may beimplemented. The LBT procedure may have the following procedure as oneof its components. The transmitting entity may draw a random number Nwithin a contention window. The size of the contention window may bespecified by the minimum and maximum value of N. The size of thecontention window may be fixed. The random number N may be employed inthe LBT procedure to determine the duration of time that the channel issensed to be idle before the transmitting entity transmits on thechannel. In an example, Category 4 (for example, LBT with randomback-off with a contention window of variable size) may be implemented.The transmitting entity may draw a random number N within a contentionwindow. The size of the contention window may be specified by a minimumand maximum value of N. The transmitting entity may vary the size of thecontention window when drawing the random number N. The random number Nmay be employed in the LBT procedure to determine the duration of timethat the channel is sensed to be idle before the transmitting entitytransmits on the channel.

LAA may employ uplink LBT at the UE. The UL LBT scheme may be differentfrom the DL LBT scheme (for example, by using different LBT mechanismsor parameters), since the LAA UL may be based on scheduled access whichaffects a UE's channel contention opportunities. Other considerationsmotivating a different UL LBT scheme include, but are not limited to,multiplexing of multiple UEs in a single subframe.

In an example, a DL transmission burst may be a continuous transmissionfrom a DL transmitting node with no transmission immediately before orafter from the same node on the same CC. A UL transmission burst from aUE perspective may be a continuous transmission from a UE with notransmission immediately before or after from the same UE on the sameCC. In an example, a UL transmission burst may be defined from a UEperspective. In an example, a UL transmission burst may be defined froman eNB perspective. In an example, in case of an eNB operating DL+UL LAAover the same unlicensed carrier, DL transmission burst(s) and ULtransmission burst(s) on LAA may be scheduled in a TDM manner over thesame unlicensed carrier. For example, an instant in time may be part ofa DL transmission burst or an UL transmission burst.

In an example embodiment, in an unlicensed cell, a downlink burst may bestarted in a subframe. When an eNB accesses the channel, the eNB maytransmit for a duration of one or more subframes. The duration maydepend on a maximum configured burst duration in an eNB, the dataavailable for transmission, and/or eNB scheduling algorithm. FIG. 10shows an example downlink burst in an unlicensed (e.g. licensed assistedaccess) cell. The maximum configured burst duration in the exampleembodiment may be configured in the eNB. An eNB may transmit the maximumconfigured burst duration to a UE employing an RRC configurationmessage.

The wireless device may receive from a base station at least one message(for example, an RRC) comprising configuration parameters of a pluralityof cells. The plurality of cells may comprise at least one cell of afirst type (e.g. license cell) and at least one cell of a second type(e.g. unlicensed cell, an LAA cell). The configuration parameters of acell may, for example, comprise configuration parameters for physicalchannels, (for example, a ePDCCH, PDSCH, PUSCH, PUCCH and/or the like).The wireless device may determine transmission powers for one or moreuplink channels. The wireless device may transmit uplink signals via atleast one uplink channel based on the determined transmission powers.

In an example embodiments, LTE transmission time may include frames, anda frame may include many subframes. The size of various time domainfields in the time domain may be expressed as a number of time unitsT_(s)=1/(15000×2048) seconds. Downlink, uplink and sidelinktransmissions may be organized into radio frames withT_(f)=307200×T_(s)=10 ms duration. In an example LTE implementation, atleast three radio frame structures may be supported: Type 1, applicableto FDD, Type 2, applicable to TDD, Type 3, applicable to LAA secondarycell operation. LAA secondary cell operation applies to frame structuretype 3.

Transmissions in multiple cells may be aggregated where one or moresecondary cells may be used in addition to the primary cell. In case ofmulti-cell aggregation, different frame structures may be used in thedifferent serving cells.

Frame structure type 1 may be applicable to both full duplex and halfduplex FDD. A radio frame is T_(f)=307200·T_(s)=10 ms long and maycomprise 20 slots of length T_(slot)=15360 T_(s)=0.5 ms, numbered from 0to 19. A subframe may include two consecutive slots where subframe icomprises of slots 2i and 2i+1.

For FDD, 10 subframes are available for downlink transmission and 10subframes are available for uplink transmissions in a 10 ms interval.Uplink and downlink transmissions are separated in the frequency domain.In half-duplex FDD operation, the UE may not transmit and receive at thesame time while there may not be such restrictions in full-duplex FDD.

Frame structure type 2 may be applicable to TDD. A radio frame of lengthT_(f)=307200·T_(s)=10 ms may comprise of two half-frames of length153600·T_(s)=5 ms A half-frame may comprise five subframes of length30720 T_(s)=1 ms. A subframe i may comprise two slots, 2i and 2i+1, oflength T_(slot)=15360·T_(s)=0.5 ms.

The uplink-downlink configuration in a cell may vary between frames andcontrols in which subframes uplink or downlink transmissions may takeplace in the current frame. The uplink-downlink configuration in thecurrent frame is obtained via control signaling.

An example subframe in a radio frame, “may be a downlink subframereserved for downlink transmissions, may be an uplink subframe reservedfor uplink transmissions or may be a special subframe with the threefields DwPTS, GP and UpPTS. The length of DwPTS and UpPTS are subject tothe total length of DwPTS, GP and UpPTS being equal to 30720·T_(s)=1 ms.

Uplink-downlink configurations with both 5 ms and 10 msdownlink-to-uplink switch-point periodicity may be supported. In case of5 ms downlink-to-uplink switch-point periodicity, the special subframemay exist in both half-frames. In case of 10 ms downlink-to-uplinkswitch-point periodicity, the special subframe may exist in the firsthalf-frame.

Subframes 0 and 5 and DwPTS may be reserved for downlink transmission.UpPTS and the subframe immediately following the special subframe may bereserved for uplink transmission.

In an example, in case multiple cells are aggregated, the UE may assumethat the guard period of the special subframe in the cells using framestructure Type 2 have an overlap of at least 1456·T_(s).

In an example, in case multiple cells with different uplink-downlinkconfigurations in the current radio frame are aggregated and the UE isnot capable of simultaneous reception and transmission in the aggregatedcells, the following constraints may apply. if the subframe in theprimary cell is a downlink subframe, the UE may not transmit any signalor channel on a secondary cell in the same subframe. If the subframe inthe primary cell is an uplink subframe, the UE may not be expected toreceive any downlink transmissions on a secondary cell in the samesubframe. If the subframe in the primary cell is a special subframe andthe same subframe in a secondary cell is a downlink subframe, the UE maynot be expected to receive PDSCH/EPDCCH/PMCH/PRS transmissions in thesecondary cell in the same subframe, and the UE may not be expected toreceive any other signals on the secondary cell in OFDM symbols thatoverlaps with the guard period or UpPTS in the primary cell.

Frame structure type 3 may be applicable to LAA secondary cell operationwith normal cyclic prefix. A radio frame is T_(f)=307200·T_(s)=10 mslong and comprises of 20 slots of length T_(slot)=15360·T_(s)=0.5 ms,numbered from 0 to 19. A subframe may comprise as two consecutive slotswhere subframe i comprises slots 2i and 2i+1.

The 10 subframes within a radio frame are available for downlinktransmissions. Downlink transmissions occupy one or more consecutivesubframes, starting anywhere within a subframe and ending with the lastsubframe either fully occupied or following one of the DwPTS durations.Subframes may be available for uplink transmission when LAA uplink issupported.

FIG. 12 shows an example 2-stage triggered grant with trigger A andtrigger B. In an example embodiment, DCI 0A/4A/0B/4B may include a bitto indicate whether an UL grant is a triggered grant or not. If it is atriggered grant, the UE may transmit after receiving a trigger (e.g. onebit set to 1) in the PDCCH DCI scrambled with CC-RNTI in a subframereceived after the subframe carrying the trigger. The timing between the2nd trigger transmitted in subframe N and an earliest UL transmissionmay be a UE capability, if the earliest UL transmission is beforesubframe N+4 (e.g. UE capability signaling between transmission insubframe N+1 and N+2 and N+3). DCI 0A/4A/0B/4B may comprise one or morefields indicating resource block assignment, modulation and codingscheme, RV, HARQ information, transmit power control command, trigger A,and/or other physical layer parameters. The trigger may be receivedduring a validation duration. The validation duration may be determinedbased on a field in the DCI including the uplink grant. The UE maymonitor CC-RNTI for a trigger during the validation duration at leastuntil the trigger is received.

DCI format 1C is used for example for LAA common information. The DCIformat 1C in an LAA cell may comprise subframe configuration for an LAAcell—j bits (e.g., j=4) indicating a number of symbols. DCI format 1Cmay further comprise other information. DCI format 1C may furthercomprise, for example, k-bits (e.g. k=5) to indicate combinations ofoffset and burst duration. In an example, a code points may include{offset, duration} combinations as follows: combinations of {{1, 2, 3,4, 6}, {1, 2, 3, 4, 5, 6} }, Reserved, no signalling of burst andoffset. The format of the bits may be defined according to a pre-definedtable. DCI format 1C may further comprise PUSCH trigger field (e.g. 1bit) to indicate a trigger for a two-stage grant. For example, value 1may indicate a trigger B and value 0 may indicate no trigger B. Reservedinformation bits may be added until the size is equal to that of format1C used for very compact scheduling of one PDSCH code-word.

In an example, if a serving cell is an LAA Scell, the UE may receivePDCCH with DCI CRC scrambled by CC-RNTI on the LAA SCell. In an example,the DCI CRC scrambled by CC-RNTI may be transmitted in the common searchspace of an LAA cell. Example PDCCH procedures are described here.

In an example, a control region of a serving cell may comprise of a setof CCEs, numbered from 0 to N_(CCE,k)−1 according, where N_(CCE,k) maybe the total number of CCEs in the control region of subframe k. The UEmay monitor a set of PDCCH candidates on one or more activated servingcells as configured by higher layer signalling for control information,where monitoring implies attempting to decode the PDCCHs in the setaccording to monitored DCI formats. A BL/CE UE may not be required tomonitor PDCCH.

In an example, the set of PDCCH candidates to monitor are defined interms of search spaces, where a search space S_(k) ^((L)) at aggregationlevel L∈{1,2,4,8} is defined by a set of PDCCH candidates. For a servingcell on which PDCCH is monitored, the CCEs corresponding to PDCCHcandidate m of the search space S_(k) ^((L)) are given byL{(Y_(k)+m′)mod └N_(CCE,k)/L┘}+i, where Y_(k) is defined below, i=0, . .. , L−1 For the common search space m′=m. For the PDCCH UE specificsearch space, for the serving cell on which PDCCH is monitored, if themonitoring UE is configured with carrier indicator field thenm′=m+M^((L))·n_(CI) where n_(CI) is the carrier indicator field value,else if the monitoring UE is not configured with carrier indicator fieldthen m′=m where m=0, . . . , M^((L))−1. M^((L)) is the number of PDCCHcandidates to monitor in the given search space.

In an example, if a UE is configured with higher layer parametercif-InSchedulingCell, the carrier indicator field value corresponds tocif-InSchedulingCell, otherwise, the carrier indicator field value isthe same as ServCellIndex. The UE may monitor one common search space ina non-DRX subframe at aggregation levels 4 and 8 on the primary cell. AUE may monitor common search space on a cell to decode the PDCCHsnecessary to receive MBMS on that cell when configured by higher layers.

In an example, if a UE is not configured for EPDCCH monitoring, and ifthe UE is not configured with a carrier indicator field, then the UE maymonitor one PDCCH UE-specific search space at aggregation levels 1, 2,4, 8 on an activated serving cell in every non-DRX subframe. If a UE isnot configured for EPDCCH monitoring, and if the UE is configured with acarrier indicator field, then the UE may monitor one or more UE-specificsearch spaces at aggregation levels 1, 2, 4, 8 on one or more activatedserving cells as configured by higher layer signalling in every non-DRXsubframe.

In an example, if a UE is configured for EPDCCH monitoring on a servingcell, and if that serving cell is activated, and if the UE is notconfigured with a carrier indicator field, then the UE may monitor onePDCCH UE-specific search space at aggregation levels 1, 2, 4, 8 on thatserving cell in non-DRX subframes where EPDCCH is not monitored on thatserving cell. If a UE is configured for EPDCCH monitoring on a servingcell, and if that serving cell is activated, and if the UE is configuredwith a carrier indicator field, then the UE may monitor one or morePDCCH UE-specific search spaces at aggregation levels 1, 2, 4, 8 on thatserving cell as configured by higher layer signalling in non-DRXsubframes where EPDCCH is not monitored on that serving cell. The commonand PDCCH UE-specific search spaces on the primary cell may overlap.

In an example, a UE configured with a carrier indicator field associatedwith monitoring PDCCH on serving cell c may monitor PDCCH configuredwith carrier indicator field and with CRC scrambled by C-RNTI in thePDCCH UE specific search space of serving cell c. A UE configured withthe carrier indicator field associated with monitoring PDCCH on theprimary cell may monitor PDCCH configured with carrier indicator fieldand with CRC scrambled by SPS C-RNTI in the PDCCH UE specific searchspace of the primary cell. The UE may monitor the common search spacefor PDCCH without carrier indicator field.

In an example, for the serving cell on which PDCCH is monitored, if theUE is not configured with a carrier indicator field, it may monitor thePDCCH UE specific search space for PDCCH without carrier indicatorfield, if the UE is configured with a carrier indicator field it maymonitor the PDCCH UE specific search space for PDCCH with carrierindicator field. If the UE is not configured with a LAA Scell, the UE isnot expected to monitor the PDCCH of a secondary cell if it isconfigured to monitor PDCCH with carrier indicator field correspondingto that secondary cell in another serving cell.

In an example, if the UE is configured with a LAA Scell, the UE is notexpected to monitor the PDCCH UE specific space of the LAA SCell if itis configured to monitor PDCCH with carrier indicator fieldcorresponding to that LAA Scell in another serving cell, where the UE isnot expected to be configured to monitor PDCCH with carrier indicatorfield in an LAA Scell; and where the UE is not expected to be scheduledwith PDSCH starting in the second slot in a subframe in an LAA Scell ifthe UE is configured to monitor PDCCH with carrier indicator fieldcorresponding to that LAA Scell in another serving cell.

In an example, for the serving cell on which PDCCH is monitored, the UEmay monitor PDCCH candidates at least for the same serving cell. A UEconfigured to monitor PDCCH candidates with CRC scrambled by C-RNTI orSPS C-RNTI with a common payload size and with the same first CCE indexn_(CCE) but with different sets of DCI information fields in the commonsearch space and/or PDCCH UE specific search space.

In an example, a UE configured to monitor PDCCH candidates in a givenserving cell with a given DCI format size with CIF, and CRC scrambled byC-RNTI, where the PDCCH candidates may have one or more possible valuesof CIF for the given DCI format size, may assume that a PDCCH candidatewith the given DCI format size may be transmitted in the given servingcell in any PDCCH UE specific search space corresponding to any of thepossible values of CIF for the given DCI format size.

In an example, if a serving cell is an LAA Scell, the UE may receivePDCCH with DCI CRC scrambled by CC-RNTI on the LAA Scell. The DCIformats that the UE may monitor depend on the configured transmissionmode of a serving cell.

Example subframe configuration for Frame Structure Type 3 are describedhere. If a UE detects PDCCH with DCI CRC scrambled by CC-RNTI insubframe n−1 or subframe n of a LAA Scell, the UE may assume theconfiguration of occupied OFDM symbols in subframe n of the LAA Scellaccording to the Subframe configuration for LAA field in the detectedDCI in subframe n−1 or subframe n.

In an example, the Subframe configuration for LAA field indicates theconfiguration of occupied OFDM symbols (e.g., OFDM symbols used fortransmission of downlink physical channels and/or physical signals) incurrent and/or next subframe according to a predefined table. If theconfiguration of occupied OFDM symbols for subframe n is indicated bythe Subframe configuration for LAA field in both subframe n−1 andsubframe n, the UE may assume that the same configuration of occupiedOFDM symbols is indicated in both subframe n−1 and subframe n.

In an example, if a UE detects PDCCH with DCI CRC scrambled by CC-RNTIin subframe n, and the UE does not detect PDCCH with DCI CRC scrambledby CC-RNTI in subframe n−1, and if the number of occupied OFDM symbolsfor subframe n indicated by the Subframe configuration for LAA field insubframe n is less than 14, the UE is not required to receive any otherphysical channels in subframe n.

In an example, if a UE does not detect PDCCH with DCI CRC scrambled byCC-RNTI containing Subframe Configuration for LAA field set to otherthan ‘1110’ and ‘1111’ in subframe n and the UE does not detect PDCCHwith DCI CRC scrambled by CC-RNTI containing Subframe Configuration forLAA field set to other than ‘1110’ and ‘1111’ in subframe n−1, the UE isnot required to use subframe n for updating CSI measurement.

In an example, the UE may detect PDCCH with DCI CRC scrambled by CC-RNTIby monitoring the following PDCCH candidates according to DCI Format IC:one PDCCH candidate at aggregation level L=4 with the CCEs correspondingto the PDCCH candidate given by CCEs numbered 0,1,2,3; one PDCCHcandidate at aggregation level L=8 with the CCEs corresponding to thePDCCH candidate given by CCEs numbered 0,1,2,3,4,5,6,7.

In an example, if a serving cell is an LAA Scell, and if the higherlayer parameter subframeStartPosition for the Scell indicates ‘s07’, andif the UE detects PDCCH/EPDCCH intended for the UE starting in thesecond slot of a subframe, the UE may assume that OFDM symbols in thefirst slot of the subframe are not occupied, and OFDM symbols in thesecond slot of the subframe are occupied. If subframe n is a subframe inwhich OFDM symbols in the first slot are not occupied, the UE may assumethat the OFDM symbols are occupied in subframe n+1.

In an example embodiment, a field in DCI format 0A/4A/0B/4B for thetriggered grant, e.g. 4-bit SF timing, may be reused to signal to the UEa subframe for transmission after reception of the trigger. When a UEreceives a trigger in subframe N, the UE may be allowed to starttransmission in subframe N+X+Y. 2 bits are reused to indicate X.X={0,1,2,3} may be indicated to the UE reusing two bits in the DCI. Ymay be given by the UL burst offset in the C-PDCCH DCI scrambled byCC-RNTI (e.g. in the same subframe where the trigger is transmitted).The UE may receive signalling in the first DCI 0A/4A/0B/4B grantindicating the number of subframes after which the grant becomesinvalid. The initial grant may become invalid if M ms after the initialgrant, no valid trigger has been received, e.g. M={8,12,16,20}. In anexample, a UE may follow the LBT type indicated by the UL grant.

In an example embodiment, C(common)-PDCCH may indicate a pair of values(UL burst duration, offset). UL burst duration may be a number ofconsecutive UL subframes belonging to the same channel occupancy. Offsetmay be the number of subframes to the start of indicated UL burst fromthe start of the subframe carrying the C-PDCCH.

In an example embodiment, an LBT procedure may be switched to an LBTbased on 25 us CCA for any UL subframe from the subframe in whichC-PDCCH was received up to and including subframes until the end of thesignalled UL burst duration, for which the eNB had already indicated toperform Category 4 LBT. In an example, a UE may not switch to 25 us CCAif part of a set of contiguously scheduled subframes without gap appearsin the UL burst indication. The UE may not be required to receive any DLsignals/channels in a subframe indicated to be a UL subframe on thecarrier. In an example, 5 bits may be employed to indicate combinationsof offset and burst duration. Example code points include {offset,duration} combinations as follows: combinations of {{1, 2, 3, 4, 6}, {1,2, 3, 4, 5, 611} }, Reserved, no signalling of burst and offset. Theformat of the bits may be defined according to a pre-defined table.

In an example embodiment, resource block assignment field in DCI0A/4A/0B/4B may be 6 bits. In an example, the 64 code points indicatedby the 6 bits may include the legacy RIV for contiguous interlaceallocation except the code points for the allocation of 7 contiguousinterlaces (70 PRBs). This set of code points may include 51 values.Additional code points may be defined for allocation of interlaces asfollows: 0,1,5,6; 2,3,4,7,8,9; 0, 5; 1, 6; 2, 7; 3, 8; 4, 9; 1, 2, 3, 4,6, 7, 8, 9. Remaining code points may be reserved.

In an example, the Activation/Deactivation MAC control element of oneoctet may be identified by a MAC PDU subheader with LCID 11000. FIG. 11shows example Activation/Deactivation MAC control elements. TheActivation/Deactivation MAC control element may have a fixed size andmay comprise of a single octet containing seven C-fields and oneR-field. Example Activation/Deactivation MAC control element with oneoctet is shown in FIG. 11. The Activation/Deactivation MAC controlelement may have a fixed size and may comprise of four octets containing31 C-fields and one R-field. Example Activation/Deactivation MAC controlelement of four octets is shown in FIG. 11. In an example, for the casewith no serving cell with a serving cell index (ServCellIndex) largerthan 7, Activation/Deactivation MAC control element of one octet may beapplied, otherwise Activation/Deactivation MAC control element of fouroctets may be applied. The fields in an Activation/Deactivation MACcontrol element may be interpreted as follows. Ci: if there is an SCellconfigured with SCellIndex i, this field may indicate theactivation/deactivation status of the SCell with SCellIndex i, else theMAC entity may ignore the Ci field. The Ci field may be set to “1” toindicate that the SCell with SCellIndex i is activated. The Ci field isset to “O” to indicate that the SCell with SCellIndex i is deactivated.R: Reserved bit, set to “0”.

In an example, if the MAC entity is configured with one or more SCells,the network may activate and deactivate the configured SCells. TheSpCell may remain activated. The network may activate and deactivate theSCell(s) by sending the Activation/Deactivation MAC control element. Inexample, the MAC entity may maintain a sCellDeactivationTimer timer fora configured SCell. sCellDeactivationTimer may be disabled for the SCellconfigured with PUCCH, if any. In example, the MAC entity may deactivatethe associated SCell upon its expiry. In an example, the same initialtimer value may apply to each instance of the sCellDeactivationTimer andit is configured by RRC. The configured SCells may be initiallydeactivated upon addition and after a handover. The configured SCGSCells are initially deactivated after a SCG change.

The MAC entity may for each TTI and for a configured SCell perform thefollowing: if the MAC entity receives an Activation/Deactivation MACcontrol element in this TTI activating the SCell, the MAC entity may inthe TTI according to a predefined timing, activate the SCell. A UE mayoperate the following for an activated SCell including: SRStransmissions on the SCell; CQI/PMI/RI/PTI/CRI reporting for the SCell;PDCCH monitoring on the SCell; PDCCH monitoring for the SCell; PUCCHtransmissions on the SCell, if configured.

If the MAC entity receives an Activation/Deactivation MAC controlelement in this TTI activating the SCell, the UE may start or restartthe sCellDeactivationTimer associated with the SCell and may triggerPHR. If the MAC entity receives an Activation/Deactivation MAC controlelement in this TTI deactivating the SCell or if thesCellDeactivationTimer associated with the activated SCell expires inthis TTI, in the TTI according to a predefined timing, the UE maydeactivate the SCell; stop the sCellDeactivationTimer associated withthe SCell; flush HARQ buffers associated with the SCell.

In an example embodiment, if the SCell is deactivated: the UE may nottransmit SRS on the SCell; not report CQI/PMI/RI/PTI/CRI for the SCell;not transmit on UL-SCH on the SCell; not transmit on RACH on the SCell;not monitor the PDCCH on the SCell; not monitor the PDCCH for the Cell;and/or not transmit PUCCH on the SCell. When SCell is deactivated, theongoing random access procedure on the SCell, if any, is aborted.

In an example embodiment, the sCellDeactivationTimer for a cell may bedisabled and there may be no need to manage sCellDeactivationTimer forthe cell and the cell may be activated or deactivated employing A/D MACCE.

In an example, when a single stage grant is configured, if PDCCH on theactivated SCell indicates an uplink grant or downlink assignment; or ifPDCCH on the Serving Cell scheduling the activated SCell indicates anuplink grant or a downlink assignment for the activated SCell: theUE/eNB may restart the sCellDeactivationTimer associated with the SCell.

In an example embodiment, an eNB may transmit one or more RRC messagescomprising one or more parameters (IEs). The one or more parameters maycomprise configuration parameters of one or more licensed cells and oneor more unlicensed cells (e.g. LAA cells). The one or more parametersmay comprise a sCellDeactivationTimer value.

For example, sCellDeactivationTimer ENUMERATED {rf2, rf4, rf8, rf16,rf32, rf64, rf128, spare} OPTIONAL. SCell deactivation timer value maybe in number of radio frames. For example, value rf4 corresponds to 4radio frames, value rf8 corresponds to 8 radio frames and so on. In anexample, E-UTRAN may configure the field if the UE is configured withone or more SCells other than the PSCell and PUCCH SCell. If the fieldis absent, the UE may delete any existing value for this field andassume the value to be set to infinity. In an example, the same valuemay apply for each SCell of a Cell Group (e.g. MCG or SCG) (theassociated functionality is performed independently for each SCell).Field sCellDeactivationTimer may not apply to an SCell, when the for thesCellDeactivationTimer is disabled for the SCell (e.g. PUCCH SCelland/or other SCells).

A UE may Support UL/DL Scheduling Combinations: Self-scheduling on DLand cross-carrier scheduling on UL. The UE to monitor for DCI formatsscheduling PUSCH of a single eLAA Scell on one UL licensed-bandscheduling cell, e.g. DCI formats 0A/0B, Formats 4A/4B (e.g ifconfigured for TM2). The UE may monitor for DCI formats scheduling LAAPDSCH on the LAA SCell, e.g. DCI formats 1A/1B/1D/1/2A/2/2B/2C/2D. Inlegacy RRC mechanisms, when cross carrier scheduling is configured byRRC for an SCell, the scheduling cell schedules both downlink and uplink(if configured) grants for the scheduled cell. In an example, the RRCsignaling and cross carrier scheduling may be enhanced. RRC signalingmay configure self-scheduling for DL and cross-carrier scheduling forUL, for example for an LAA cell. For example, a new parameter in thecross-carrier scheduling configuration parameters may indicate whetherthe cross-carrier scheduling is for both downlink scheduling and uplinkscheduling or is for uplink scheduling (and DL is self-scheduled). In anexample, a licensed cell may be configured for cross-carrier schedulingan unlicensed (e.g. LAA) cell.

The IE CrossCarrierSchedulingConfig may used to specify theconfiguration when the cross carrier scheduling is used in a cell. In anexample, the IE CrossCarrierScheduling Config may comprise cif-Presence,schedulingCellId, and pdsch-Start. In an example, the IECrossCarrierSchedulingConfig may comprise cif-Presence,schedulingCellId, pdsch-Start, and cif-InSchedulingCell. In an example,cif-Presence may be used to indicate whether carrier indicator field ispresent (value true) or not (value false) in PDCCH/EPDCCH DCI formats.In an example, pdsch-Start field may indicate the starting OFDM symbolof PDSCH for the concerned SCell. In an example, values 1, 2, 3 areapplicable when dl-Bandwidth for the concerned SCell is greater than 10resource blocks, values 2, 3, 4 are applicable when dl-Bandwidth for theconcerned SCell is less than or equal to 10 resource blocks. In anexample, cif-InSchedulingCell field may indicate the CIF value used inthe scheduling cell to indicate this cell. In an example,schedulingCellId field may indicates which cell signals the downlinkallocations and/or uplink grants, if applicable, for the concernedSCell. In case the UE is configured with DC, the scheduling cell is partof the same cell group (e.g. MCG or SCG) as the scheduled. In anexample, an IE in IE CrossCarrierSchedulingConfig of an RRC message mayindicate self-scheduling on DL and cross-carrier scheduling on UL (forexample for an LAA cell). In an example, an IE in IECrossCarrierSchedulingConfig of an RRC message may indicatecross-carrier scheduling on both downlink and uplink.

There is an uplink HARQ entity at a MAC entity for a serving cell withconfigured uplink, which may maintain a number of parallel HARQprocesses allowing transmissions to take place continuously whilewaiting for the HARQ feedback on the successful or unsuccessfulreception of previous transmissions. In an example, when the physicallayer is configured for uplink spatial multiplexing, there may be twoHARQ processes associated with a given TTI. Otherwise there is one HARQprocess associated with a given TTI. At a given TTI, if an uplink grantis indicated for the TTI, the HARQ entity identifies the HARQprocess(es) for which a transmission may take place. It also routes thereceived HARQ feedback (ACK/NACK information), MCS and resource, relayedby the physical layer, to the appropriate HARQ process(es).

In an example, in asynchronous HARQ operation, a HARQ process may beassociated with a TTI based on the received uplink DCI grant. Except forNB-IoT, an asynchronous HARQ process may be associated with a HARQprocess identifier. For UL transmission with UL grant in RAR, HARQprocess identifier 0 may be used. HARQ feedback may not be applicablefor asynchronous UL HARQ.

In an example embodiment, when TTI bundling is configured, the parameterTTI_BUNDLE_SIZE may provide the number of TTIs of a TTI bundle. TTIbundling operation may rely on the HARQ entity for invoking the sameHARQ process for each transmission that is part of the same bundle.Within a bundle HARQ retransmissions are non-adaptive and triggeredwithout waiting for feedback from previous transmissions according toTTI_BUNDLE_SIZE. The HARQ feedback of a bundle is only received for thelast TTI of the bundle (i.e the TTI corresponding to TTI_BUNDLE_SIZE),regardless of whether a transmission in that TTI takes place or not(e.g. when a measurement gap occurs). A retransmission of a TTI bundlemay be a TTI bundle. TTI bundling may not be supported when the MACentity is configured with one or more SCells with configured uplink. Inan example, uplink HARQ operation may be asynchronous for NB-IoT UEs, BLUEs or UEs in enhanced coverage except for the repetitions within abundle.

In an example embodiment, for NB-IoT UEs, BL UEs or UEs in enhancedcoverage, the parameter ul_repetition_number provides the number oftransmission repetitions within a bundle. For a bundle,ul_repetition_number is set to a value provided by lower layers.Bundling operation may rely on the HARQ entity for invoking the sameHARQ process for a transmission that is part of the same bundle. Withina bundle HARQ retransmissions may be non-adaptive and may be triggeredwithout waiting for feedback from previous transmissions according toul_repetition_number. An uplink grant corresponding to a newtransmission or a retransmission of the bundle may be received after thelast repetition of the bundle. A retransmission of a bundle may be abundle. In an example, TTI bundling may not be supported for RNcommunication with the E-UTRAN in combination with an RN subframeconfiguration.

In an example, for transmission of Msg3 during Random Access TTIbundling may not apply. For NB-IoT UEs, BL UEs or UEs in enhancedcoverage, uplink repetition bundling is used for transmission of Msg3.For a TTI, the HARQ entity may identify the HARQ process(es) associatedwith this TTI, and for an identified HARQ process. In an example, if anuplink grant has been indicated for this process and this TTI: performprocess A, else perform process B.

In an example process A, if the received grant was not addressed to aTemporary C-RNTI on PDCCH and if the NDI provided in the associated HARQinformation has been toggled compared to the value in the previoustransmission of this HARQ process; or if the uplink grant was receivedon PDCCH for the C-RNTI and the HARQ buffer of the identified process isempty; or if the uplink grant was received in a Random Access Response:a) if there is a MAC PDU in the Msg3 buffer and the uplink grant wasreceived in a Random Access Response: obtain the MAC PDU to transmitfrom the Msg3 buffer; else: obtain the MAC PDU to transmit from the“Multiplexing and assembly” entity; b) deliver the MAC PDU and theuplink grant and the HARQ information to the identified HARQ process; c)instruct the identified HARQ process to trigger a new transmission.Else: a) deliver the uplink grant and the HARQ information (redundancyversion) to the identified HARQ process; b) instruct the identified HARQprocess to generate an adaptive retransmission.

In an example process B, if the HARQ buffer of this HARQ process is notempty: instruct the identified HARQ process to generate a non-adaptiveretransmission.

In an example, when determining if NDI has been toggled compared to thevalue in the previous transmission the MAC entity may ignore NDIreceived in uplink grants on PDCCH for its Temporary C-RNTI.

In an example embodiment, for a TTI, the HARQ entity may identify theHARQ process(es) associated with this TTI, and for an identified HARQprocess: if an uplink grant has been indicated for this process and thisTTI, and the uplink grant is for a new transmission, the MAC entity inthe UE may obtain the MAC PDU to transmit from the Multiplexing andassembly entity; deliver the MAC PDU and the uplink grant and the HARQinformation to the identified HARQ process; and instruct the identifiedHARQ process to trigger a new transmission. If the uplink grant is for aretransmission, the MAC entity in the UE may deliver the uplink grantand the HARQ information (redundancy version) to the identified HARQprocess; and instruct the identified HARQ process to generate anadaptive retransmission.

In an example, the Power Headroom reporting procedure may be used toprovide the serving eNB with information about the difference betweenthe nominal UE maximum transmit power and the estimated power for UL-SCHtransmission per activated serving cell and also with information aboutthe difference between the nominal UE maximum power and the estimatedpower for UL-SCH and PUCCH transmission on SpCell and PUCCH SCell.

A base station may transmit one or more RRC messages comprisingconfiguration parameters of a plurlaity of cells. The configurationpaameters may comprise power headroom configuraiton parameters forconfiguring power headroom reporting. RRC may control power headroomreporting by configuring two timers periodicPHR-Timer andprohibitPHR-Timer, and by signalling dl-PathlossChange which sets thechange in measured downlink pathloss and the required power backoff dueto power management to trigger a PHR.

A Power Headroom Report (PHR) may be triggered if at least one of thefollowing events occur: a) prohibitPHR-Timer expires or has expired andthe path loss has changed more than dl-PathlossChange dB for at leastone activated serving cell of any MAC entity which is used as a pathlossreference since the last transmission of a PHR in this MAC entity whenthe MAC entity has UL resources for new transmission; b)periodicPHR-Timer expires; c) upon configuration or reconfiguration ofthe power headroom reporting functionality by upper layers, which is notused to disable the function; d) activation of an SCell of any MACentity with configured uplink; e) addition of the PSCell; f)prohibitPHR-Timer expires or has expired, when the MAC entity has ULresources for new transmission, and the following is true in this TTIfor any of the activated serving cells of any MAC entity with configureduplink: there are UL resources allocated for transmission or there is aPUCCH transmission on this cell, and the required power backoff due topower management for this cell has changed more than dl-PathlossChangedB since the last transmission of a PHR when the MAC entity had ULresources allocated for transmission or PUCCH transmission on this cell.In an example, a MAC entity may avoid triggering a PHR when the requiredpower backoff due to power management decreases only temporarily (e.g.for up to a few tens of milliseconds) and it may avoid reflecting suchtemporary decrease in the values of PCMAX,c/PH when a PHR is triggeredby other triggering conditions.

In an example embodiment, an uplink DCI grant may be a two-stage DCIgrant. In a two-stage DCI grant, a timing of a trigger B and otherparameters may determine the TTI for uplink transmissions. Whentwo-stage DCI grants are implemented, the TTI of uplink transmissisonscorresponding to the uplink DCI grant is not known (at the time the DCIgrant is received). In a two-stage DCI grant, if a trigger B is notreceived during a trigger validation duration after the two-stage DCIgrant, the two-stage DCI grant may be invalidated. Current PHR processdepends on the TTI that is employed for uplink TB transmission, which isnot known to the UE at the time the DCI grant is received. If thecurrent timing for calculating/determining PHR values, creating a MACPDU including the PHR, and executing other PHR processes are implementedwhen two-stage grants are implemented, the PHR implementation results inuplink transmission issues and additional UE processing. Additionally,current PHR processes do not address a scenario when the two-stage DCIgrant is invalidated (when the trigger B is not received during atrigger validation duration).

There is a need to provide an enhanced PHR process for uplinktransmissions when two-stage uplink DCI grants are implemented in awireless network. Example embodiments enhance calculation/determinationof PHR values, generation of MAC PDU including a PHR, and PHR timermanagement when two stage grants are implemented. Example embodimentsenhances PHR processes when two-stage grants are implemented.

In order to transmit on the UL-SCH, the MAC entity may have a validuplink grant (except for non-adaptive HARQ retransmissions) which the UEmay receive dynamically on the PDCCH or in a Random Access Response orwhich may be configured semi-persistently. To perform requestedtransmissions, the MAC layer may receive HARQ information from lowerlayers. In an example, when the physical layer is configured for uplinkspatial multiplexing, the MAC layer may receive up to two grants (oneper HARQ process) for the same TTI from lower layers.

In an example, two-stage DCI grants may be implemented. A wirelessdevice may receive a first downlink control information (DCI)comprising: a first trigger field indicating that the first DCI istriggered in response to a second DCI indicating a second trigger(trigger B); and/or a field indicating a validation duration forreceiving the second DCI via a cell. The first trigger field (trigger Afield) may be set to 1 to indicate that the first DCI is a triggeredDCI.

There is a need to develop MAC/PHY PHR processes when a two-stage DCIgrant is implemented. In the current procedures, the DCI grant may beinvalidated when trigger B is not received during a validation duration.The physical layer may monitor for trigger B. Uplink transmissionscorresponding to the DCI grant are not performed if trigger B is notreceived. In an example embodiment of the invention, the UE may deliverthe uplink DCI grant and the associated HARQ information to the HARQentity for a TTI in response to receiving an uplink DCI grant regardlessof whether the trigger B is received or not. In an example, the UE maydeliver the uplink grant (e.g. as soon as it is available) and theassociated HARQ information to the MAC entity for a TTI when a DCI grantis received even before a trigger B is received. This process providesadditional flexibility and enables a UE MAC entity to start MAC PDUgeneration and processing before trigger B is received. A MAC entity mayconsider the transmission to have been performed anyway regardless ofwhether the trigger B is received or not.

In an example, if the MAC entity has a C-RNTI, a Semi-PersistentScheduling C-RNTI, or a Temporary C-RNTI, the MAC entity may for a TTIand for a serving cell (e.g. belonging to a TAG that has a runningtimeAlignmentTimer), for a grant received for this TTI: if a first stageof a two-stage uplink DCI grant for a TTI and this serving cell has beenreceived on the PDCCH for the MAC entity's C-RNTI (or Temporary C-RNTI),the UE may deliver the uplink DCI grant and the associated HARQinformation to the HARQ entity for the TTI. This is done regardless ofwhether the trigger B is received or not.

In a two-stage grant, the TTI for transmission in the resoucesidentified in the uplink DCI grant may depend on when a DCI including atrigger B is received in a common search space of the LAA cell. The UEmay process the MAC PDU before receiving the trigger B. In some examplescenarios, the TTI for transmission may be, e.g., one or two subframesafter receiving the trigger, and depending on a UE capability, a UE maynot have enough time to construct and process the MAC PDU afterreceiving the trigger. The UE may construct and process (e.g. multiplexand/or encode, etc) the MAC PDU before the trigger B is received. Uponreceiving the trigger B the UE may perform some physical layerprocessing and map the TB on the physical resouces. Depending on thecontent of the DCI grant (which may determine a minimum subframesbetween the trigger B and transmission TTI) and/or depending on a UEcapability, a UE may be able to construct and process the MAC PDU beforeor after receiving a trigger B.

In an example embodiment, an uplink DCI grant may be a two-stage DCIgrant. In a two-stage DCI grant, a timing of a trigger B and otherparameters may determine the TTI for uplink transmission. When two-stageDCI grants are implemented, the TTI of uplink transmissisonscorresponding to the uplink DCI grant is not known (at the time the DCIgrant is received). In a two-stage DCI grant, if the trigger B is notreceived during a trigger validation duration after the two-stage DCIgrant, the two-stage DCI grant may be invalidated.

In an example, the UE may deliver the uplink grant (as soon as it isavailable) and the associated HARQ information to the MAC entity for aTTI when a DCI grant is received even before the trigger B is received.This provides additional flexibility and enables a UE/MAC entity tostart generation of MAC PDU including a PHR before trigger B isreceived. A MAC entity may consider the transmission to have beenperformed anyway regardless of whether the trigger B is received or not.The UE may construct and process (e.g. multiplex and/or encode, etc) theMAC PDU comprising a PHR MAC CE before a corresponding trigger B isreceived.

In an example embodiment, if the MAC entity has UL resources allocatedfor new transmission for a TTI, the MAC entity may if the power headroomreporting procedure determines that at least one PHR has been triggeredand not cancelled, and if the allocated UL resources can accommodate theMAC control element (plus its subheader) for PHR which the MAC entity isconfigured to transmit (as a result of logical channel prioritization),the MAC entity may obtain PHR values, instruct the multiplexing andassembly procedure to generate and transmit a PHR MAC control element,and start or restart prohibitPHR-Timer and may cancel triggered PHR(s).

An exmaple diagram is shown in FIG. 13. In an example embodiment, the UEmay perform MAC PDU packet processing after the first DCI grant of atwo-stage DCI grant is received. The UE may process the first DCI grantand inform the HARQ entity about the grant. The UE may construct/createthe MAC PDU (if a new transmission) comprising a PHR and inform the HARQentity about the first DCI grant. In an example embodiment, a UE mayinvalidate the first DCI grant if no trigger B is received within atrigger validation duration, as shown in FIG. 15.

In an example, depending on the content of the DCI grant (which maydetermine a minimum subframes between the trigger B and transmissionTTI) and/or depending on a UE capability, a UE may construct and processthe MAC PDU before or after receiving the trigger B. In an example,depending on a parameter in the grant (parameter X, 2 bits) thatdetermines a minimum time between the trigger and the TTI for the uplinktransmission, the UE may determine whether the UE generates and/orprocesses the MAC PDU before or after the trigger B. In an example, whenthe minimum time between the trigger B and TTI for TB transmission isabove k subframe (e.g. k=2, 4), the UE may generate and/or process theMAC PDU after it receives the trigger B. In an example embodiment, theMAC PDU may be processed before the trigger B is received regardless ofthe value of the parameter X.

In an example embodiment, a MAC entity may instruct the identified HARQprocess for new transmission or adaptive retransmission. A UE MAC entitydoes not need to know about the actual TTI of the PHY transmission whena two-stage DCI grant is received. A MAC entity may record the first DCIgrant and may process the grant before receiving a trigger B. In anexample, if the first DCI grant is invalidated due to not receiving atrigger B, the UE MAC entity does not necessarily need to know aboutthis. A UE MAC entity may not inform the HARQ entity that the first DCIgrant is invalidated (when the MAC PDU is processed before the trigger).

In an example embodiment, if the MAC PDU is “a new transmission” andincludes PHR, the UE may cancel MAC PHR triggers according to the PHRprocedures. The UE may start the corresponding PHR timers according tothe PHR procedures. In an example embodiment, the UE may create a MACPDU including the PHR, cancel MAC PHR trigger(s) and start thecorresponding PHR timers according to the PHR procedures even if the DCIgrant is invalidated (e.g. by the PHY layer) due to not receiving thetrigger B in the trigger validation duration. When the DCI grant isinvalidated, the MAC PDU (TB) is not transmitted in any TTI. However,the MAC PDU TB including the PHR may be stored in the HARQ buffer. A MACprocess may be performed regardless of whether the trigger B is receivedor not.

In an example embodiment, a MAC entity may obtain PHR values, instructthe multiplexing and assembly procedure to generate and transmit a PHRMAC control element, start the corresponding PHR according to the PHRprocedures in a TTI. The TTI in which the PHR timers are restarted needto be determined. In an example, the UE may obtain PHR values, instructthe multiplexing and assembly procedure to generate and transmit a PHRMAC control element, and start the corresponding PHR timers at apredetermined reference TTI relative to the TTI of the uplink DCI grant.The UE and/or eNB may maintain PHR timer(s) and restart PHR timer(s) inthe same reference TTI (if eNB maintains the timer). In an exampleembodiment, when the uplink DCI grant is received in subframe n, the UEmay obtain PHR values, instruct the multiplexing and assembly procedureto generate and transmit a PHR MAC control element, and start thecorresponding PHR timers in reference subframe n+k, wherein k is apredefined number, for example k=0, 1, 2 or 4.

Example embodiments provide an enhanced PHR process in which a PHRprocess is executed at a reference subframe which may be different fromthe TTI for uplink transmission. This enhanced process is performedregardless of whether the first DCI grant is invalidated or not.Implementation of the reference subframe, which could be different fromuplink transmission subframe, provides advantages to both base stationand the wireless device. The enhanced PHR process eliminates the impactof the uncertainty in the reception of trigger B and the timing of theuplink transmission TTI. Implementation of legacy PHR processesincreases UE processing requirements when a two-stage grant isimplemented in a wireless network. Example embodiments provides anenhanced PHR process for such implementation.

A wireless device may receive a first uplink DCI grant of a two-stagegrant at a first subframe n. The MAC entity may perform a PHR processfor a reference subframe (TTI) of n+k (e.g. k=4). If the MAC entity hasUL resources allocated for new transmission; and if the power headroomreporting procedure determines that at least one PHR has been triggeredand not cancelled, and; if the allocated UL resources can accommodatethe MAC control element for PHR which the MAC entity is configured totransmit, plus its subheader, as a result of logical channelprioritization: the MAC entity may perform at least the following: a)obtain one or more values of Type 1 power headrooms for one or moreserving cells; obtain one or more values of Type 2 power headrooms forone or more serving cells (e.g. PCell, PSCell, PUCCH SCell); instructthe multiplexing and assembly procedure to generate and transmit a PHRMAC control element based on value(s) reported by the physical layer;start or restart periodicPHR-Timer; start or restart prohibitPHR-Timer;cancel triggered PHR(s). If it is the first UL resource allocated for anew transmission since the last MAC reset, the MAC entity may startperiodicPHR-Timer. The wireless device may store the MAC PDU comprisingthe PHR in a HARQ buffer. The wireless device may transmit the MAC PDUcomprising the PHR in an uplink subframe in response to receiving asecond DCI comprising a trigger B. The timing of the uplink subframe maydepend at least on a timing of the second DCI and/or a subframe offsetvalue.

In an example, a base station may transmit to a wireless device at leastone message comprising configuration parameters of a plurality of cellscomprising an LAA secondary cell configured with uplink transmissions.The wireless device receives a first uplink DCI grant of a two-stageuplink grant in a first subframe n for transmission in an uplinksubframe of a serving cell c. The first uplink DCI grant comprises atleast a first field and a first trigger field. The first field in thefirst uplink DCI grant indicates an assignment of resource blocks fortransmissions via an uplink subframe of the LAA cell. A first triggerindicates that the first uplink DCI grant is triggered in response to asecond DCI indicating a second trigger (trigger B). A timing of theuplink subframe is determined employing at least the second DCI.

The UE may report power headroom on the LAA cell using the first uplinkDCI grant. The MAC entity may perform a PHR process for a reference TTIof n+k (e.g. k=4). In an example, the UE may obtain PHR values, instructthe multiplexing and assembly procedure to generate and transmit a PHRMAC control element, and start the corresponding PHR timers at areference subframe n+k (e.g. k=4).

In an example, for a serving cell, computation/determination of PHRvalue(s) for a cell in a subframe depends on whether a MAC PDUtransmission is considered for the cell in the subframe. In an example,a UE may construct and process the MAC PDU for transmission before orafter receiving the trigger B. In an example, when a time between thetrigger B and TTI for TB transmission is above k subframe (e.g. k=2, 4),the UE may generate and/or process the MAC PDU for transmission after itreceives the trigger B.

In an example, when a trigger B for a serving cell is received atsubframe n or earlier, the UE determines a PHR value for the servingcell assuming that a transmission is performed in the referencesubframe. In an example, when a trigger B for a serving cell is receivedafter subframe n, the UE determines a PHR value for the serving cellassuming that a transmission is not performed in the reference subframe.

The UE may process the uplink DCI grant and inform the HARQ entity aboutthe uplink DCI grant. The UE may construct/create the PDU (if a newtransmission) comprising a PHR and inform the HARQ entity about theuplink DCI grant. In an example embodiment, a UE may invalidate theuplink DCI grant if no trigger is received within a trigger validationduration.

In an example, if the MAC entity has UL resources allocated for newtransmission, and if the power headroom reporting procedure determinesthat at least one PHR has been triggered and not cancelled, and; if theallocated UL resources can accommodate the MAC control element for PHRwhich the MAC entity is configured to transmit, plus its subheader, as aresult of logical channel prioritization, the MAC entity may execute apower headroom process based on the RRC configuration parameters.

The MAC entity may start or restart periodicPHR-Timer; start or restartprohibitPHR-Timer; cancel triggered PHR(s); and if it is the first ULresource allocated for a new transmission since the last MAC reset,start periodicPHR-Timer.

If extendedPHR is configured: for activated serving cell(s) withconfigured uplink: obtain the value of the Type 1 power headroom; if theMAC entity has UL resources allocated for transmission on this servingcell for this TTI: obtain the value for the corresponding PCMAX,c fieldfrom the physical layer; if simultaneousPUCCH-PUSCH is configured:obtain the value of the Type 2 power headroom for the PCell; obtain thevalue for the corresponding PCMAX,c field from the physical layer; andinstruct the multiplexing and assembly procedure to generate andtransmit an Extended PHR MAC control element for extendedPHR based onthe values reported by the physical layer.

If extendedPHR2 is configured: for activated serving cell(s) withconfigured uplink: obtain the value of the Type 1 power headroom. if theMAC entity has UL resources allocated for transmission on this servingcell for this TTI: obtain the value for the corresponding PCMAX,c fieldfrom the physical layer. If a PUCCH SCell is configured and activated:obtain the value of the Type 2 power headroom for the PCell and PUCCHSCell; obtain the values for the corresponding PCMAX,c fields from thephysical layer. Else if simultaneousPUCCH-PUSCH is configured for thePCell: obtain the value of the Type 2 power headroom for the PCell;obtain the value for the corresponding PCMAX,c field from the physicallayer. Instruct the Multiplexing and Assembly procedure to generate andtransmit an Extended PHR MAC control element for extendedPHR2 accordingto configured ServCellIndex and the PUCCH(s) for the MAC entity based onthe values reported by the physical layer;

If dualConnectivityPHR is configured: for activated serving cell(s) withconfigured uplink associated with any MAC entity: obtain the value ofthe Type 1 power headroom; if this MAC entity has UL resources allocatedfor transmission on this serving cell for this TTI or if the other MACentity has UL resources allocated for transmission on this serving cellfor this TTI and phr-ModeOtherCG is set to real by upper layers: obtainthe value for the corresponding PCMAX,c field from the physical layer.If simultaneousPUCCH-PUSCH is configured: obtain the value of the Type 2power headroom for the SpCell; obtain the value for the correspondingPCMAX,c field for the SpCell from the physical layer. Obtain the valueof the Type 2 power headroom for the SpCell of the other MAC entity. Ifphr-ModeOtherCG is set to real by upper layers: obtain the value for thecorresponding PCMAX,c field for the SpCell of the other MAC entity fromthe physical layer. Instruct the Multiplexing and Assembly procedure togenerate and transmit a Dual Connectivity PHR MAC control element asdefined in subclause 6.1.3.6b based on the values reported by thephysical layer.

If regular power headroom is configured: obtain the value of the Type 1power headroom from the physical layer; instruct the Multiplexing andAssembly procedure to generate and transmit a PHR MAC control elementbased on the value reported by the physical layer.

In an example embodiment, an uplink DCI grant may be a two-stage DCIgrant. In a two-stage DCI grant, a timing of a trigger B and otherparameters may determine the TTI for uplink transmissions. Whentwo-stage DCI grants are implemented, the TTI of uplink transmissisonscorresponding to the uplink DCI grant is not known (at the time the DCIgrant is received). In a two-stage DCI grant, if a trigger B is notreceived during a trigger validation duration after the two-stage DCIgrant, the two-stage DCI grant may be invalidated. Current BSR processdepends on the TTI that is employed for uplink TB transmission, which isnot known to the UE at the time the DCI grant is received. The timingfor calculating/determining BSR values, creating a MAC PDU including theBSR, and executing other BSR processes when two-stage grants areimplemented results in uplink transmission issues and additional UEprocessing. Additionally, current BSR processes do not address ascenario when the two-stage DCI grant is invalidated (when the trigger Bis not received during a trigger validation duration).

There is a need to provide an enhanced BSR process for uplinktransmissions when two-stage uplink DCI grants are implemented in awireless network. Example embodiments enhance calculation/determinationof BSR values, generation of MAC PDU including a BSR, and BSR timermanagement when two stage grants are implemented. Example embodimentsenhances BSR processes when two-stage grants are implemented.

In an example, the UE may deliver the uplink grant (as soon as it isavailable) and the associated HARQ information to the MAC entity for aTTI when a DCI grant is received even before the trigger B is received.This provides additional flexibility and enables a UE/MAC entity tostart generation of MAC PDU including a BSR before trigger B isreceived. A MAC entity may consider the transmission to have beenperformed anyway regardless of whether the trigger B is received or not.The UE may construct and process (e.g. multiplex and/or encode, etc) theMAC PDU comprising a BSR MAC CE before a corresponding trigger B isreceived.

An exmaple diagram is shown in FIG. 14. In an example embodiment, the UEmay perform MAC PDU packet processing after the first DCI grant of atwo-stage DCI grant is received. The UE may process the first DCI grantand inform the HARQ entity about the grant. The UE may construct/createthe MAC PDU (if a new transmission) comprising a BSR and inform the HARQentity about the first DCI grant. In an example embodiment, a UE mayinvalidate the first DCI grant if no trigger B is received within atrigger validation duration, as shown in FIG. 15.

In an example embodiment, if the MAC PDU is “a new transmission” andincludes BSR, the UE may cancel MAC BSR trigger and start thecorresponding BSR timers according to the BSR procedures. In an exampleembodiment, the UE may construct a MAC PDU comprising a BSR and cancelMAC BSR trigger according to the BSR procedures even if the DCI grant isinvalidated (e.g. by the PHY layer) due to not receiving the trigger inthe trigger validation duration. When the DCI grant is invalidated, theMAC PDU (TB) comprising BSR is not transmitted in any TTI. However, theTB may be stored in the HARQ buffer. A MAC process may be performedregardless of whether the trigger B is received or not.

In an example embodiment, a MAC entity may instruct the identified HARQprocess for new transmission or adaptive retransmission. A UE MAC entitydoes not need to know about the actual TTI of the PHY transmission whena two-stage DCI grant is received. A MAC entity may record the first DCIgrant and may process the grant before receiving a trigger B. In anexample, if the first DCI grant is invalidated due to not receiving atrigger B, the UE MAC entity does not necessarily need to know aboutthis. A UE MAC entity may not inform the HARQ entity that the first DCIgrant is invalidated (when the MAC PDU is processed before the trigger).

In an example embodiment, the UE may construct a MAC PDU including a BSRand start the corresponding BSR timers according to the BSR proceduresin a reference TTI. The reference TTI in which the MAC PDU comprisingBSR is generated and the BSR timers are restarted need to be determined.In an example, the UE may generate a MAC PDU including a BSR and startthe corresponding BSR timers at a predetermined reference TTI relativeto a subframe in which the uplink DCI grant is received. The UE and/oreNB may maintain BSR timer(s) and restart BSR timer(s) in the samereference TTI (if eNB maintains BSR timers). In an example embodiment,when an uplink DCI grant is received in a first subframe n,corresponding BSR timer(s) may be restarted in a reference subframe n+k,wherein k is a predefined number, for example k=0, 1, 2 or 4. BSRsdetermined for a reference TTI may reflect the buffer status after MACPDUs have been built for this reference TTI.

Example embodiments provide an enhanced BSR process in which a BSRprocess is executed at a reference subframe which may be different fromthe TTI for uplink transmission. This enhanced process is performedregardless of whether the first DCI grant is invalidated or not.Implementation of the reference subframe, which could be different fromuplink transmission subframe, provides advantages to both base stationand the wireless device. The enhanced BSR process eliminates the impactof the uncertainty in the reception of trigger B and the timing of theuplink transmission TTI. Implementation of legacy BSR processesincreases UE processing requirements when a two-stage grant isimplemented in a wireless network. Example embodiments provides anenhanced BSR process for such implementation.

In an example embodiment, a UE may generate a BSR and start thecorresponding BSR timers according to the BSR procedures in a referenceTTI. The reference TTI in which BSR is generated and the BSR timers arerestarted need to be determined. In an example, the UE may generate aBSR and start the corresponding BSR timer(s) when the trigger isreceived. If the trigger is not received, MAC may generate a BSR andrestart the corresponding timers when trigger is invalidated. The UEand/or eNB may maintain the BSR timer and restart the BSR timer in thesame reference TTI (if eNB maintains the BSR timer). In an exampleembodiment, when the uplink DCI grant is received in a first subframe n,and a trigger B is received in subframe n+k, then the correspondingtimer may be restarted in subframe n+k, for example k=4 or 8, or 12.BSRs determined for a reference TTI may reflect the buffer status afterMAC PDUs have been built for this reference TTI.

The UE may process the uplink DCI grant and inform the HARQ entity aboutthe uplink DCI grant. The UE may construct/create the PDU (if a newtransmission) comprising a BSR and inform the HARQ entity about theuplink DCI grant. In an example embodiment, a UE may invalidate theuplink DCI grant if no trigger is received within a trigger validationduration.

In an example embodiment, a two stage DCI grant may be invalidated andcorresponding at least one TB may not be transmitted. Implementation oflegacy mechanisms may result in ignoring the two stage DCI grant and theat least one TB. This may result in inefficiencies and additional UEprocessing power. There is a need to implement enhanced MAC and PHYprocedures for a scenario wherein a two-stage grant is invalidated whenthe second trigger is not received. Example embodiments reduces UEprocessing power and enhances uplink transmission for a two-stage grant,especially when the two-stage grant is invalidated.

FIG. 16 shows an example embodiment for enhancing HARQ procedures when atwo-stage DCI grant is implemented. In an example embodiment, when atrigger B is not received within a trigger validation duration, thefirst DCI grant in a two-stage DCI grant may be invalidated. In anexample embodiment, the UE/eNB may store/save the value of the NDI andthe HARQ process ID of the invalidated DCI grant and consider the storedNDI for the next DCI grant corresponding to the same HARQ process ID inorder to determine whether NDI is toggle or not.

A wireless device may receive a first downlink control information (DCI)grant comprising a HARQ process ID equal to k. The first DCI grant maycomprise: a first trigger field, and a validation field. The firsttrigger field may indicate that the first DCI is triggered in responseto a second DCI comprising a second trigger. The validation field mayindicate a validation duration for receiving the second DCI validatingthe first DCI. A medium access entity (MAC) may create one or more firsttransport blocks (TBs) in response to the first DCI. Examples are shownin FIG. 12 to FIG. 16. The wireless device may monitor for the secondDCI during at least a portion of the validation duration. For example,the wireless device may monitor for the second DCI including the triggeruntil the trigger is received during the validation duration. Inresponse to the monitoring not detecting the second DCI, the first DCI(2StageGrant) may be invalidated and transmission of the one or moretransport blocks dropped (no TB PHY transmission). The MAC entity mayconsider, that the transmission of the one or more transport blocks tohave been performed anyway. For example, the HARQ process ID and the NDImay be stored; and the one or more first TBs may be stored in a HARQbuffer.

In an example, when a UE receives an uplink DCI grant indicating an NDIvalue and a HARQ process ID, the UE determines whether the NDI providedin the associated HARQ process has been toggled compared to the value inthe previous DCI grant of this HARQ process. This is regardless ofwhether the previous DCI grant is invalidated or not. When the NDI isnot toggled, the NDI indicates that the DCI grant is for retransmissionof the previous invalidated DCI grant. In an example, when the NDI istoggled, the NDI indicates that the DCI grant is for a new transmissionof a new TB. For example, a third DCI indicating a same value of theHARQ process ID equal to k may be received. Uplink signals may betransmitted in response to the third DCI. The wireless device may employthe stored NDI to determine an adaptive-retransmission of the one ormore first transport blocks or a new transmission of one or more secondtransport blocks. In example FIG. 16, the third DCI indicates aretransmission of the at least one TB associated with the missed(invalidated) grant.

FIG. 16 shows an example, wherein NDI is not toggled (the grant on theright) compared with the invalidated DCI grant (the DCI grant in themiddle), but it is toggled compared with the previous valid DCI grant(the DCI grant on the left) in FIG. 16. The grant on the right is forretransmission of the TB that was constructed and stored in the HARQbuffer but could not be transmitted (was dropped) due to the invalidatedDCI grant.

According to various embodiments, a device (such as, for example, awireless device, off-network wireless device, a base station, and/or thelike), may comprise one or more processors and memory. The memory maystore instructions that, when executed by the one or more processors,cause the device to perform a series of actions. Embodiments of exampleactions are illustrated in the accompanying figures and specification.Features from various embodiments may be combined to create yet furtherembodiments.

FIG. 17 is an example flow diagram as per an aspect of an embodiment ofthe present disclosure. A wireless device receives, in a first subframe,a first downlink control information (DCI) at 1710. The first DCI maycomprise: a first field indicating an assignment of resource blocks fortransmissions via an uplink subframe of a licensed assisted access (LAA)cell; and a first trigger indicating that the first DCI is triggered inresponse to a second DCI indicating a second trigger, wherein a timingof the uplink subframe is determined based at least on the second DCI.At 1720, the wireless device may determine power headroom values of areference subframe for transmission via the resource blocks of theuplink subframe of the LAA cell. The reference subframe may be differentfrom the uplink subframe. The reference subframe may be a subframe aftera predetermined number of subframes from the first subframe. A secondDCI may be received at 1730. At 1740, the wireless device may transmit,via the uplink subframe of the LAA cell, a transport block comprising apower headroom report comprising the power headroom values of thereference subframe.

According to an embodiment, the wireless device may further receive atleast one message comprising configuration parameters of a plurality ofcells comprising the LAA cell, wherein the configuration parameterscomprise at least one power headroom configuration parameter. Accordingto an embodiment, the wireless device may further restart a powerheadroom timer in response to at least the first DCI. According to anembodiment, the wireless device may further restart, in the referencesubframe, a power headroom timer in response to at least the first DCI.According to an embodiment, the second DCI may be received via a commonsearch space of a control channel of the LAA cell, and the second DCImay correspond to a pre-defined radio network temporary identifier(RNTI). According to an embodiment, power headroom values may comprise:a Type 1 power headroom value; and a Type 2 power headroom value.According to an embodiment, the predetermined number may be four.According to an embodiment, the second DCI may comprise: a subframeformat field indicating a subframe format; and a subframe fieldindicating a subframe offset. According to an embodiment, the second DCImay be received via a common search space of a downlink control channel.

According to an embodiment, power headroom values may comprise a firstpower headroom value of a first LAA cell; The first power headroom valuemay be determined assuming that at least one transport block istransmitted in the reference subframe, if the wireless device receives afirst trigger on or before the first subframe indicating transmission ofthe at least one transport block in the reference subframe. The firstpower headroom value may be determined assuming that at least onetransport block is not transmitted in the reference subframe, if thewireless device receives a first trigger after the first subframeindicating transmission of the at least one transport block in thereference subframe.

FIG. 18 is an example flow diagram as per an aspect of an embodiment ofthe present disclosure. A wireless device may receive, in a firstsubframe, a first downlink control information (DCI) at 1810. The firstDCI may comprise: a first field indicating an assignment of resourceblocks for transmissions via an uplink subframe of a licensed assistedaccess (LAA) cell; and a first trigger indicating that the first DCI istriggered in response to a second DCI indicating a second trigger,wherein a timing of the uplink subframe is determined based at least onthe second DCI. At 1820, the wireless device may determine buffer statusvalues of a reference subframe for transmission via the resource blocksof the uplink subframe of the LAA cell. At 1830, the second DCI may bereceived. At 1840, the wireless device may transmit, via the uplinksubframe of the LAA cell, a transport block comprising a buffer statusreport comprising the buffer status values of the reference subframe.According to an embodiment, the reference subframe may be different fromthe uplink subframe. According to an embodiment, the reference subframemay be a predetermined number of subframes after the first subframe.

In this specification, “a” and “an” and similar phrases are to beinterpreted as “at least one” and “one or more.” In this specification,the term “may” is to be interpreted as “may, for example.” In otherwords, the term “may” is indicative that the phrase following the term“may” is an example of one of a multitude of suitable possibilities thatmay, or may not, be employed to one or more of the various embodiments.If A and B are sets and every element of A is also an element of B, A iscalled a subset of B. In this specification, only non-empty sets andsubsets are considered. For example, possible subsets of B={cell1,cell2} are: {cell1}, {cell2}, and {cell1, cell2}.

In this specification, parameters (Information elements: IEs) maycomprise one or more objects, and each of those objects may comprise oneor more other objects. For example, if parameter (IE) N comprisesparameter (IE) M, and parameter (IE) M comprises parameter (IE) K, andparameter (IE) K comprises parameter (information element) J, then, forexample, N comprises K, and N comprises J. In an example embodiment,when one or more messages comprise a plurality of parameters, it impliesthat a parameter in the plurality of parameters is in at least one ofthe one or more messages, but does not have to be in each of the one ormore messages.

Many of the elements described in the disclosed embodiments may beimplemented as modules. A module is defined here as an isolatableelement that performs a defined function and has a defined interface toother elements. The modules described in this disclosure may beimplemented in hardware, software in combination with hardware,firmware, wetware (i.e hardware with a biological element) or acombination thereof, all of which are behaviorally equivalent. Forexample, modules may be implemented as a software routine written in acomputer language configured to be executed by a hardware machine (suchas C, C++, Fortran, Java, Basic, Matlab or the like) or amodeling/simulation program such as Simulink, Stateflow, GNU Octave, orLabVIEWMathScript. Additionally, it may be possible to implement modulesusing physical hardware that incorporates discrete or programmableanalog, digital and/or quantum hardware. Examples of programmablehardware comprise: computers, microcontrollers, microprocessors,application-specific integrated circuits (ASICs); field programmablegate arrays (FPGAs); and complex programmable logic devices (CPLDs).Computers, microcontrollers and microprocessors are programmed usinglanguages such as assembly, C, C++ or the like. FPGAs, ASICs and CPLDsare often programmed using hardware description languages (HDL) such asVHSIC hardware description language (VHDL) or Verilog that configureconnections between internal hardware modules with lesser functionalityon a programmable device. Finally, it needs to be emphasized that theabove mentioned technologies are often used in combination to achievethe result of a functional module.

The disclosure of this patent document incorporates material which issubject to copyright protection. The copyright owner has no objection tothe facsimile reproduction by anyone of the patent document or thepatent disclosure, as it appears in the Patent and Trademark Officepatent file or records, for the limited purposes required by law, butotherwise reserves all copyright rights whatsoever.

While various embodiments have been described above, it should beunderstood that they have been presented by way of example, and notlimitation. It will be apparent to persons skilled in the relevantart(s) that various changes in form and detail can be made thereinwithout departing from the spirit and scope. In fact, after reading theabove description, it will be apparent to one skilled in the relevantart(s) how to implement alternative embodiments. Thus, the presentembodiments should not be limited by any of the above describedexemplary embodiments. In particular, it should be noted that, forexample purposes, the above explanation has focused on the example(s)using LAA communication systems. However, one skilled in the art willrecognize that embodiments of the disclosure may also be implemented ina system comprising one or more TDD cells (e.g. frame structure 2 and/orframe structure 1). The disclosed methods and systems may be implementedin wireless or wireline systems. The features of various embodimentspresented in this disclosure may be combined. One or many features(method or system) of one embodiment may be implemented in otherembodiments. Only a limited number of example combinations are shown toindicate to one skilled in the art the possibility of features that maybe combined in various embodiments to create enhanced transmission andreception systems and methods.

In addition, it should be understood that any figures which highlightthe functionality and advantages, are presented for example purposesonly. The disclosed architecture is sufficiently flexible andconfigurable, such that it may be utilized in ways other than thatshown. For example, the actions listed in any flowchart may bere-ordered or only optionally used in some embodiments.

Further, the purpose of the Abstract of the Disclosure is to enable theU.S. Patent and Trademark Office and the public generally, andespecially the scientists, engineers and practitioners in the art whoare not familiar with patent or legal terms or phraseology, to determinequickly from a cursory inspection the nature and essence of thetechnical disclosure of the application. The Abstract of the Disclosureis not intended to be limiting as to the scope in any way.

Finally, it is the applicant's intent that only claims that include theexpress language “means for” or “step for” be interpreted under 35U.S.C. 112. Claims that do not expressly include the phrase “means for”or “step for” are not to be interpreted under 35 U.S.C. 112.

What is claimed is:
 1. A method comprising: transmitting during a firstsubframe, by a base station, an uplink grant triggered in response totransmitting a trigger during a validation duration, the uplink grantindicating resource blocks; transmitting, during the validationduration, the trigger indicating an uplink subframe for reception viathe resource blocks; and receiving, during the uplink subframe and viathe resource blocks, a power headroom value determined for a referencesubframe, wherein the reference subframe: is after the first subframe;and is before the uplink subframe.
 2. The method of claim 1, furthercomprising transmitting, by the base station, at least one messagecomprising configuration parameters of a plurality of cells comprising alicensed assisted access (LAA) cell, wherein: the configurationparameters comprise at least one power headroom configuration parameter;and the uplink subframe is an uplink subframe of the LAA cell.
 3. Themethod of claim 1, wherein a downlink control information (DCI)comprises the uplink grant, wherein a wireless device restarts a powerheadroom timer in response to receiving the DCI.
 4. The method of claim1, wherein: the trigger is transmitted in a downlink control information(DCI) that is transmitted via a common search space of a control channelof a licensed assisted access (LAA) cell; the DCI corresponds to apre-defined radio network temporary identifier (RNTI); and the uplinksubframe is an uplink subframe of the LAA cell.
 5. The method of claim1, wherein the power headroom value comprises one or more of: a Type 1power headroom value; and a Type 2 power headroom value.
 6. The methodof claim 1, wherein: the reference subframe is a predetermined number ofsubframes later than the first subframe; and the predetermined number isfour.
 7. The method of claim 1, wherein the trigger is transmitted in adownlink control information that comprises: a subframe format fieldindicating a subframe format; and a subframe field indicating a subframeoffset.
 8. The method of claim 1, wherein the trigger is transmitted ina downlink control information that is received via a common searchspace of a downlink control channel.
 9. The method of claim 1, wherein:the power headroom value comprises a first power headroom value of afirst cell; the first power headroom value is determined assuming thatat least one transport block is received in the reference subframe, ifthe base station transmits the trigger on or before the first subframeindicating transmission of the at least one transport block in thereference subframe; and the first power headroom value is determinedassuming that at least one transport block is not received in thereference subframe, if the base station transmits the trigger after thefirst subframe indicating transmission of the at least one transportblock in the reference subframe.
 10. A base station comprising: one ormore processors; memory storing instructions that, when executed by theone or more processors, cause the base station to: transmit during afirst subframe, by a base station, an uplink grant triggered in responseto transmitting a trigger during a validation duration, the uplink grantindicating resource blocks; transmit, during the validation duration,the trigger indicating an uplink subframe for reception via the resourceblocks; and receive, during the uplink subframe and via the resourceblocks, a power headroom value determined for a reference subframe,wherein the reference subframe: is after the first subframe; and isbefore the uplink subframe.
 11. The base station of claim 10, whereinthe instructions, when executed by the one or more processors, cause thebase station to transmit at least one message comprising configurationparameters of a plurality of cells comprising a licensed assisted access(LAA) cell, wherein: the configuration parameters comprise at least onepower headroom configuration parameter; and the uplink subframe is anuplink subframe of the LAA cell.
 12. The base station of claim 10,wherein a downlink control information (DCI) comprises the uplink grant,wherein a wireless device restarts a power headroom timer in response toreceiving the DCI.
 13. The base station of claim 10, wherein: thetrigger is received in a downlink control information (DCI) that isreceived via a common search space of a control channel of a licensedassisted access (LAA) cell; the DCI corresponds to a pre-defined radionetwork temporary identifier (RNTI); and the uplink subframe is anuplink subframe of the LAA cell.
 14. The base station of claim 10,wherein the power headroom value comprises one or more of: a Type 1power headroom value; and a Type 2 power headroom value.
 15. The basestation of claim 10, wherein: the reference subframe is a predeterminednumber of subframes later than the first subframe; and the predeterminednumber is four.
 16. The base station of claim 10, wherein the trigger isreceived in a downlink control information that comprises: a subframeformat field indicating a subframe format; and a subframe fieldindicating a subframe offset.
 17. The base station of claim 10, whereina downlink control information is received via a common search space ofa downlink control channel.
 18. The base station of claim 10, wherein:the power headroom value comprises a first power headroom value of afirst cell; the first power headroom value is determined assuming thatat least one transport block is received in the reference subframe, ifthe base station transmits the trigger on or before the first subframeindicating transmission of the at least one transport block in thereference subframe; and the first power headroom value is determinedassuming that at least one transport block is not received in thereference subframe, if the base station transmits the trigger after thefirst subframe indicating transmission of the at least one transportblock in the reference subframe.
 19. A system comprising: a base stationcomprising: one or more first processors; first memory storing firstinstructions that, when executed by the one or more first processors,cause the base station to: transmit during a first subframe, by a basestation, an uplink grant triggered in response to transmitting a triggerduring a validation duration, the uplink grant indicating resourceblocks; transmit, during the validation duration, the trigger indicatingan uplink subframe for reception via the resource blocks; and receive,during the uplink subframe and via the resource blocks, a power headroomvalue determined for a reference subframe, wherein the referencesubframe: is after the first subframe; and is before the uplinksubframe; and a wireless device comprising: one or more secondprocessors; second memory storing second instructions that, whenexecuted by the one or more second processors, cause the wireless deviceto: receive the uplink grant; receive, the trigger; and transmit, thepower headroom value.
 20. The system of claim 19, wherein the firstinstructions, when executed by the one or more first processors, causethe base station to transmit at least one message comprisingconfiguration parameters of a plurality of cells comprising a licensedassisted access (LAA) cell, wherein the configuration parameterscomprise at least one power headroom configuration parameter and theuplink subframe is an uplink subframe of the LAA cell.